AU775226B2 - Isolation and identification of novel polymerases - Google Patents

Description

AUSTRALIA

Patents Act 1990 Diversa Corporation

ORIGINAL

COMPLETE SPECIFICATION DIVISIONAL PATENT Invention Title: Isolation and identification of novel polymerases The following statement is a full description of this invention including the best method of performing it known to us:- WO 99/07837 PCT/US98/17152 ISOLATION AND IDENTIFICATION OF NOVEL POLYMERASES Field of the Invention This invention relates to newly identified polynucleotides, polypeptides encoded by such polynucleotides. the use of such polynucleotides and polypeptides, as well as the production and isolation of such polynucleotides and polypeptides. More particularly, the polypeptides of the present invention have been identified as polymerases Backround of the Invention Thermophilic bacteria have received considerable attention as sources of highly active and thermostable enzymes. Recently, the most extremely thermophilic organotrophic eubacteria presently known have been isolated and characterized. These bacteria, which belong to the genus is thermotoga, are fermentative microorganisms metabolizing a variety of carbohydrates (Huber, R.

and Stetter, in Ballows, et al., The Procaryotes, 2nd Ed., Springer-Verlaz, New York, pgs. 3809-3819 (1992)).

In Huber et al., 1986, Arch. Microbiol. 144:324-333 the isolation of the bacterium S Thermotoga maritima is described. T. maritima is a eubacterium that is strictly anaerobic, rod- .20 shaped, fermentative, hyperthermophilic, and grows between 55*C and 90 0 C, with an optimum growth temperature of about 80 0 C. This eubacterium has been isolated from geothermally heated sea floors in Italy and the Azores. T. maritima cells have a sheath-like structure and monotrichous flagellation. T. maritima is classified in the eubacterium kingdom by virtue of having murein and fatty acid-containing lipids, diphtheria-toxin-resistant elongation factor 2, an RNA polymerase subunit pattern, and sensitivity to antibiotics.

Since, to date, most organisms identified from the archaeal domain are thermophiles or hyperthermophiles, archaea are also considered a fertile source of thermophilic enzymes.

la- WO 99/07837 PCT/US98/17152 Summary of the Invention The present invention provides polynucleotides and polypeptides encoded thereby which have been identified as polymerase enzymes. In accordance with one aspect of the present invention, there s oided novel enzymes. as \we! as active fragments. ana!ogs and derivatvs thereof In accordance with another aspect of the present invention, there are provided isolated nucleic acid molecules encoding enzymes of the present invention including mRNAs, DNAs, cDNAs. genomic DNAs as well as active analogs and fragments of such enzymes.

In accordance with another aspect of the present invention there are provided isolated nucleic acid molecules encoding mature polypeptides expressed by the DNA in SEQ ID Nos:1. 3. 5. 7. 9.

11.

In accordance with yet a further aspect of the present invention, there is provided a process for producing such polypeptide by recombinant techniques comprising culturing recombinant prokaryotic andior eukarvotic host cells, containing a nucleic acid sequence encoding an enzyme of the present invention, under conditions promoting expression of said enzyme and subsequent recovery of said enzyme.

In accordance with yet a further aspect of the present invention, there is provided a process for utilizing such enzymes, or polynucleotide encoding such enzymes for polymerizing DNA.

20 In accordance with yet a further aspect of the present invention, there is also provided nucleic acid probes comprising nucleic acid molecules of sufficient length to specifically hybridize to a nucleic acid sequence of the present invention.

In accordance with yet a further aspect of the present invention. there is provided a process for utilizingsuch enzymes, or polynucleotides encoding such enzymes, for in vitro purposes related to scientific research, for example, to generate probes for identifying similar sequences which might encode similar enzymes from other organisms.

These and other aspects of the present invention should be apparent to those skilled in the art from the teachings herein.

ee** WO 99/07837 PCTIUS98/17152 Brief Description of the Drawiinas The following drawinuis are illustrative of embodiments of the inv'ention and are not meant to limit the scope of the invention as encompassed by the claims. Sequencin2 was per-formed using a 3 78 automated D 1 NA scquencer (App lied B:iosv-,stems. Inc.*,# FIGURE I shows the nucleotide and deduced amino acid sequence of DNA polvmerase (3)pyI) from AmmonifexY degensfi.

-0 FIGURE 2 shows the nucleotide and deduced amino acid sequence of DNA polymerase (I PY2) from Aprolobus fumnari us.

FIGURE 3 shows the nucleotide and deduced amino acid sequence of DNA polymerase 1) from Archaeoglobus lithorrophicus.

FIGURE 4 shows the nucleotide and deduced amino acid sequence of DNA polymerase (23PYI) from Metallosplhaera prunae.

FIGURE 5 shows the nucleotide and deduced amino acid sequence of DNA polymerase (29PY 1) from Desuofurococcus.

:FIGURE 6 shows the nucleotide and deduced amino acid sequence. of DNA polymerase (34PY 1) fifbmAquyfe VF-S.

1 3- WO 99/07837 PCT/US98/17152 Description of the Preferred Embodiments The term "gene" means the segment of DNA involved in producing a poiypeptide chain: it includes regions preceding and following the coding region (leader and trailer, as well as intervening s sequences (intronsi between individual coding segments (exons).

A coding sequence is "operably linked to" another coding sequence when RNA polymerase will transcribe the two coding sequences into a single mRNA. which is then translated into a single polypeptide having amino acids derived from both coding sequences. The coding sequences need not be contiguous to one another so long as the expressed sequences are ultimately processed to produce the desired protein.

"Recombinant" enzymes refer to enzymes produced by recombinant DNA techniques: i.e..

produced from cells transformed by an exogenous DNA construct encoding the desired enzyme.

"Synthetic" enzymes are those prepared by chemical synthesis.

A DNA "coding sequence of' or a "nucleotide sequence encoding" a particular enzyme. is a DNA sequence which is transcribed and translated into an enzyme when placed under the control of appropriate regulatory sequences. A "promotor sequence" is a DNA regulatory region capable of binding RNA polymerase in a cell and initiating transcription of a downstream direction) coding sequence. The promoter is part of the DNA sequence. This sequence region has a start codon at its 3' terminus. The promoter sequence does include the minimum number of bases :i 20 where elements necessary to initiate transcription at levels detectable above background.

However, after the RNA polymerase binds the sequence and transcription is initiated at the start codon terminus with a promoter). transcription proceeds downstream in the 3" direction.

Within the promotor sequence will be found a transcription initiation site (conveniently defined by mappmig with nuclease SI) as well as protein binding domains (consensus sequences) responsible for the binding of RNA polymerase.

The present invention provides purified thermostable enzymes that catalyze DNA synthesis by addition of deoxynucleotides to the 3 end of a polynucleotide chain, using a complementary polynucleotide strand as a template. An exemplary purified enzyme is a polvmerase derived from an organism referred herein as "Ammonifex degensii KC4" is a gram negative.

30 chemolithoautotrophic eubacteria and has a very high temperature optimum. Ammonifex deensii KC4 was discovered in a deep sea isolate from the Middle Atlantic Ridge. Ammonifex degensii

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WO 99/07837 PCT/US98/17152 KC4 grows optimally at 70C and pH 7.0 in a low salt medium. This exemplary cnzyme is shown in Figure 1.

The polynucleotide encoding SEQ ID NO: was originally recovered from a genomic gene library derived from Arnmonifex degensii KC4 as described beiow it contains an open readine frame encoding a protein of 867 amino acid residues.

In one embodiment, the representative polymerase of SEQ ID NO:1 of the present invention has a molecular weight of about 95.6 kilodaltons as measured by SDS-PAGE gel electrophoresis and an inferred molecular weight from the nucleotide sequence of the gene. This purified enzyme may be used to polymerize DNA where desired. The polymerase enzyme of the present invention has a very high thermostability and has the closest homology to polymerase from Bacillus stearomiermophilus with 56% identity and 75% similarity at the amino acid level.

In accordance with an aspect of the present invention, there are provided isolated nucleic acid molecules (polynucleotides) which encode for the mature enzymes having the deduced amino acid sequence of Figures 1-6 and SEQ ID NOs:l, 3, 5. 7, 9, 11.

This invention, in addition to the isolated nucleic acid molecule encoding an polymerase enzyme disclosed in Figures 1-6 (SEQ ID NOs:l, 3. 5. 7. 9, 11). also provides substantially similar sequences. Isolated nucleic acid sequences are substantially similar if: they are capable of hybridizing undef stringent conditions, hereinafter described, to SEQ ID NO:1; or (ii) 20 they encode DNA sequences which are degenerate to SEQ ID NO:1. Degenerate DNA sequences encode the amino acid sequence of SEQ ID NO:2. but have variations in the nucleotide coding sequences. As used herein, "substantially similar" refers to the sequences having similar identity Sto the sequences of the instant invention. The riucleotide sequences that are substantially similar can be identified by hybridization or by sequence comparison. Eniz

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fie sequences that are 25 substantially similar can be identified by one or more of the following: proteolytic digestion. gel electrophoresis and.or microsequencing. One means for isolating a nucleic acid molecule encoding a polymerase enzyme is to probe a genomic gene library with a natural or artificially designed probe using art recognized procedures (see. for example: Current Protocols in Molecular Biology, Ausubel F.M. et aL (EDS.) Green Publishing Company Assoc. and John o Wiley Interscience, New York. 1989. 1992). It is appreciated to one skilled in the art that SEQ SID NO:1, or fragments thereof (comprising at least 10 contiguous nucleotides and at least

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WO 99/07837 PCT/US98/17152 complementary to a target sequence), is a particularly useful probe. Other particular useful probes for this purpose are hybridizable fragments to the sequences of SEQ ID NO:1 comprising at least 10 contiguous nucleotides and at least 70% complementary to a target sequence).

With respect to nucleic acid sequences which hybridize to specific nucleic acid sequences disclosed herein, hybridization may be carried out under conditions of reduced stringency.

medium stingency or even stringent conditions. As an example of oligonucleotide hybridization.

a polymer membrane containing immobilized denatured nucleic acid is first prehybridized for minutes at 45'C in a solution consisting of 0.9 M NaCI, 50 mM NaH,PO,. pH 7.0. 5.0 mM Na,EDTA. 0.5% SDS. 10X Denhardt's. and 0.5 mg/mL polvriboadenylic acid. Approximately 2 X 10 cpm (specific activity 4-9 X 16 cpm/lig) of P end-labeled oligonucleotide probe are then added to the solution. After 12-16 hours of incubation, the membrane is washed for minutes at room temperature in IX SET (150 mM NaCI, 20 mM Tris hydrochloride, pH 7.8, 1 mM Na,EDTA) containing 0.5% SDS, followed by a 30 minute wash in fresh IX SET at Tm- 10C for the oligo-nucleotide probe. The membrane is then exposed to auto-radiographic film for detection of hybridization signals.

In nucleic acid hybridization reactions. the conditions used to achieve a particular level of stringency will vary. depending on the nature of the nucleic acids being hybridized. For example, the length. degree of complementarity, nucleotide sequence composition GC v. AT content).

and nucleic acid type RNA v. DNA) of the hybridizing regions of the nucleic acids can be considered in selecting hybridization conditions. An additional consideration is whether one of the nucleic acids is immobilized, for example, on a filter.

.an example of progressively higher stringency conditions is as follows: 2 x SSC/0.1% SDS at about room temperature (hybridization conditions): 0.2 x SSC/0.1% SDS at about -room temperature (low stringency conditions); 0.2 x SSC/0.1% SDS at about 42"C (moderate stringency conditions): and 0.1 x SSC at about 68*C (high stringency conditions). Washing can be carried out using only one of these conditions, high stringency conditions, or each of the conditions can be used. for 10-15 minutes each. in the order listed above, repeating any or all of the steps listed. However, as mentioned above, optimal conditions will vary, depending on the panicular hybridization reaction involved, and can be determined empirically.

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WO 99/07837 PCT/US98/17152 "ldentity" as the term is used herein, refers to a polynucleotide sequence which comprises a percentage of the same bases as a reference polynucleotide (SEQ ID NO:1). For example. a s polynuclectide which is at least 90% identical to a reference po.ynucleotide. has "polnucleotide bases which are identical in 90% of the bases which make up the reference polynucleotide and may have different bases in 10% of the bases which comprise that polynucleotide sequence.

The present invention also relates to polynucleotides which differ from the reference polynucleotide such that the changes are silent changes, for example the changes do not alter the o1 amino acid sequence encoded by the polynucleotide. The present invention also relates-to nucleotide changes which result in amino acid substitutions, additions, deletions. fusions and truncations in the enzyme encoded by the reference polynucleotide (SEQ ID NO:1). In a preferred aspect of the invention these enzymes retain the same biological action as the enzyme encoded by the reference polynucleotide.

1s It is also appreciated that such probes can be and are preferably labeled with an analytically detectable reagent to facilitate identification of the probe. Useful reagents include but are not limited to radioactivity, fluorescent dyes or enzymes capable of catalyzing the formation of a detectable product. The probes are thus useful to isolate complementary copies of DNA from other animal sources or to screen such sources for related sequences.

20 The present invention provides substantially pure polymerase enzymes. The term "substantially pure" is used herein to describe a molecule, such as a polypeptide a polymerase polypeptide, or a fragment thereof) that is substantially free of other proteins, lipids.

carbohydrates, nucleic acids, and other biological materials with which it is naturally associated.

For example, a substantially pure molecule, such as a polypeptide. can be at least 60%. bV dry weight, the molecule of interest. The purity of the polypeptides can be determined using standard methods including. polyacrylamide gel electrophoresis SDS-PAGE), column chromatography high performance liquid chromatography (HPLC)), and amino- terminal amino acid sequence analysis.

Polymerase polypeptides included in the invention can have one of the amino acid so30 sequences of polymerases shown in Figures 1 through 6 (SEQ ID Nos:2. 4. 6. 8. 10, 12), for example, the amino acid sequence of Ammonifex degensii KC4 (SEQ ID NO:2). Polymerase WO 99/07837 PCT/US98/17152 polypcptides. such as those isolated from Ammonifex dcgensii KC4. can be characterized by polymerizing DNA.

Also included in the invention are polypeptides having sequences that are -substantially identical" to the sequence of a polymcrase polypeptide. such as one of SEQ ID NO:2. e. SEQ ID NO:4. A "substantially identical" amino acid sequence is a sequence that differs from a reference sequence only by conservative amino acid substitutions, for example, substitutions of one amino acid for another of the same class substitution of one hydrophobic amino acid.

such as isoleucine. valine. leucine, or methionine, for another, or substitution of one polar amino acid for another, such as substitution of arginine for lysine, glutamic acid for aspanic acid. or glutamine for asparagine). or by one or more non-conservative substitutions. deletions. or insertions. provided that the polypeptide retains at least one polymerase-specific activity or a polymerase-specific epitope. For example, one or more amino acids can be deleted from a polymerase polypeptide. resulting in modification of the structure of the polypeptide. without is significantly altering its biological activity. For example, amino- or carboxyl-terminal amino acids that are not required for polymerase biological activity, can be removed. Such modifications can result in the development of smaller active polymerase polypeptides.

Other polymerase polypeptides included in the invention are polypeptides having amino acid sequences that are at least 50% identical to the amino acid sequence of a polymerase 20 polypeptide. such as any of polymerases in SEQ ID Nos:2. 4.'6 10. 12, SEQ ID NO:12.

The length of comparison in determining amino acid sequence homology can be. for example.

at least 15 amino acids. for example. at least 20. 25. or 35 amino acids. Homology can be measured using standard sequence analysis software Sequence Analysis Software Package of the Genetics Computer Group, University of Wisconsin Biotechnology Center, 1710 University 25 Avenue. Madison. WI 53705; also see Ausubel, et al.. supra). Stich procedures and algorithms include, for example, a BLAST program (Basic Local Alignment Search Tool at the National Center for Biological Information), ALIGN, AMAS (Analysis of Multiply Aligned Sequences).

AMPS (Protein Multiple Sequence Alignment), ASSET (Aligned Segment Statistical Evaluation Tool). BANDS. BESTSCOR, BIOSCAN (Biological Sequence Comparative Analysis Node), BLIMPS (BLocks IMProved Searcher). FASTA. Intervals Points. BMB. CLUSTAL V.

CLUSTAL W. CONSENSUS, LCONSENSUS, WCONSENSUS, Smith-Waterman algorithm.

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WO 99/07837 PCT/US98/17152 DARWIN. Las Vegas algorithm. FNAT (Forced Nucleotide Alignment Tool). Framcalign.

Framescarch. DYNAMIC. FILTER. FSAP (Fristensky Sequence Analysis Package). GAP (Global Alignment Program). GENAL. GIBBS. GenQuest. ISSC (Sensitive Sequence Comparison), LALIGN (Local Sequence Alignment). LCP (Local Content Programl. MACAW (Multiple Alignment Construction Analysis Workbench). MAP (Multiple Alignment Program). MBLKP.

MBLKN. PIMA (Pattern-Induced Multi-sequence Alignment). SAGA (Sequence Alignmnet by Genetic ALgorithm) and WHAT-IF.

The invention also includes fragments of polymerase polypeptides that retain at least one polymerase-specific activity or epitope. Polymerase activity can be assayed by examining the polymerizing of DNA. For example, a polymerase polypeptide fragment containing. at least 8-10 amino acids can be used as an immunogen in the production of polymerase-specific antibodies. The fragment can contain, for example, an amino acid sequence that is conserved in polymerases, and this amino acid sequence can contain amino acids that are conserved in is polymerases. Such fragments can easily be identified by comparing the sequences of polymerases found in Figures 1-X. In addition to their use as peptide immunogens. the above-described polymerase fragments can be used in immunoassays. such as ELISAs. to detect the presence of polymerase-specific antibodies in samples.

The polymerase polypeptides of the invention can be obtained using any of several 2 standard methods. For example, polymerase polypeptides can be produced in a standard recombinant expression systems (see below). chemically synthesized (this approach may be limited to small polymerase peptide fragments), or purified from organisms in which they are naturally expressed.

The invention also provides isolated nucleic acid molecules that encode the polymerase 25 polypeptides described above, as well as fragments thereof. For example. nucleic acids that encode any of SEQ ID NOs:l, 3, 5, 7, 9, 11 are included in the invention. These nucleic acids can contain naturally occurring nucleotide sequences, or sequences that differ from those of the naturally occurring nucleic acids that encode polymerases. but encode the same amino acids, due to the degeneracy of the genetic code. The nucleic acids of the invention can contain DNA or RNA nucleotides. or combinations or modifications thereof. Exemplary nucleic acids of the invention are shown in SEQ ID NO:1.

WO 99/07837 PCT/US98/17152 By "isolated nucleic acid" is meant a nucleic acid. a DNA or RN.\ molecule, that is not immediately contiguous with the 5' and 3' flanking sequences with which it normally is immediately contiguous when present in the naturally occurring genome of the organism from which it is derived. The term thus describes, for example. a nucleic acid that is incorporated into a vector. such as a plasmid or viral vector: a nucleic acid that is incorporated into the genome of a heterologous cell (or the genome of a homologous cell. but at a site different from that at which it naturally occurs); and a nucleic acid that exists as a separate molecule. a DNA fragment produced by PCR amplification or restriction enzyme digestion, or an RNA molecule produced by in tirro transcription. The term also describes a recombinant nucleic acid that forms part of a hybrid gene encoding additional polypeptide sequences that can be used. for example.

in the production of a fusion protein.

The nucleic acid molecules of the invention can be used as templates in standard methods for production of polymerase gene products polymerase RNAs and polymerase is polypeptides). In addition, the nucleic acid molecules that encode polymerase polypeptides (and fragments thereof) and related nucleic acids, such as nucleic acids containing sequences that are complementary to. or that hybridize to. nucleic acids encoding polymerase polypeptides. or fragments thereof fragments containing at least 10, 12, 15, 20. or 25 nucleotides): and (2) nucleic acids containing sequences that hybridize to sequences that are complementary to nucleic 20 acids encoding polymerase polypeptides. or fragments thereof fragments containing at least 10. 12. 15. 20. or 25 nucleotides): can be used in methods focused on their hybridization properties. For example. as is described in further detail below: such nucleic acid molecules can be used in the following methods: PCR methods for synthesizing polymerase nucleic acids.

methods f6r detecting the presence of an polymefase nucleic acid in a sample. screening methods 25 for identifying nucleic acids encoding new polymerase family members. Oligonucleotide probes useful for screening methods are from 10 to about 150 nucleotides in length. Further. such probes are preferably 10 to about 100 nucleotides in length and more preferably from 10 to about 50 nucleotides in length.

The invention also includes methods for identifying nucleic acid molecules that encode 30 members of the polymerase polypeptide family in addition to SEQ ID NOs:1. 3. 5. 7. 9. 11. In these methods, a sample, a nucleic acid library, such as a cDNA library, that contains a

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WO 99/07837 PCT/US98/17152 nucleic acid encoding a polymerase polypeptide is screened with a polymerasc-spccific probe: a poiymerase-specific nucleic acid probe. Polymerase-specific nucleic acid probes are nucleic acid molecules molecules containing DNA or RNA nucleotides. or combinations or modifications thereof) that specifically hybridize to nucleic acids encoding polymerase polypeptides. or to complementary sequences thereof. The term "'polymerase-specific probe". in the context of this method of invention, refers to probes that bind to nucleic acids encoding polymerase polypeptides, or to complementary sequences thereof, to a detectably greater extent than to nucleic acids encoding other enzymes, or to complementary sequences thereof.

The invention facilitates production of polymerase-specific nucleic acid probes. Methods for obtaining such probes can be designed based on the amino acid sequences shown in Figure 1. The probes. which can contain at least 10. 15, 25. 35. 50. 100, or 150 nucleotides. can be produced using any of several standard methods (see, Ausubel. er al., supra). For example, preferably, the probes are generated using .PCR amplification methods. In these methods, primers are designed that correspond to polymerase-conserved sequences (see Figure which can include polymerase-specific amino acids, and the resulting PCR product is used as a probe to screen a nucleic acid library, such as a cDNA library.

The coding sequences for the polymerase enzymes of the present invention were identified by preparing an Ammonifex degensii KC4 genomic DNA library, for example, and screening the 20 library for the clones having polymerase activity. Such methods for constructing a genomic gene library are well-known in the art. One means, for example, comprises shearing DNA isolated from Ammonifex degensii KC4 by physical disruption. A small amount of the sheared DNA is checked on an agarose gel to verify that the majority of the DNA is in the desired size range (approxinately 3-6 kb). The DNA is then blunt ended using Mung Bean Nuclease. incubated at S 2s 37C and phenol/chloroform extracted. The DNA is then methylated using Eco RJ Methylase.

Eco RI linkers are then ligated to the blunt ends through the use of T4 DNA ligase and incubation at 4'C. The ligation reaction is then terminated and the DNA is cut-back with Eco restriction enzyme. The DNA is then size fractionated on a sucrose gradient following procedures known in the art, for example, Maniatis, et al., Molecular Cloning. Cold Spring Harbor Press, New York. 1982, which is hereby incorporated by reference in its entirety.

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WO 99/07837 PCT/US98/17152 A plate assay is then performed to get an approximate concentration of the DNA.

Ligation reactions are then performed and 1 ul of the ligation reaction is packaged to construct a library. Packaging. for example, may occur through the use of purified (.gt1 I phage arms cut with EcoRl and DNA cut with EcoRI after attaching EcoRI linkers. The DNA and (.gtl 1 arms are ligated with DNA ligase. The ligated DNA is then packaged into infectious phage particles.

The packaged phages are used to infect E. coli cultures and the infected cells are spread on agar plates to yield plates carrying thousands of individual phage plaques. The library is then amplified.

Fragments of the full length gene of the present invention may be used as a hybridization probe for a cDNA or a genomic library to isolate the full length DNA and to isolate other DNAs which have a high sequence similarity to the gene or similar biological activity. Probes of this type have at least 10, preferably at least 15, and even more preferably at least 30 bases and may contain, for example, at least 50 or more bases. The probe may also be used to identify a DNA clone corresponding to a full length transcript and a genomic clone or clones that contain the complete gene including regulatory and promotor regions, exons. and introns.

The isolated nucleic acid sequences and other enzymes may then be measured for retention of biological activity characteristic to the enzyme of the present invention, for example, in an assay for detecting enzymatic polymerase activity. Such enzymes include truncated formis of 20 polymerase. and variants such as deletion and insertion variants.

The polynucleotide of the present invention may be in the form of DNA which DNA o includes cDNA, genomic DNA, and synthetic DNA. The DNA may be double-stranded or single-sranded, and if single stranded may be the coding strand or non-coding (anti-sense) strand.

The coding sequence which encodes the mature enzyme may be identical to the coding sequences *25 shown in Figures 1-6, or may be a different coding sequence which coding sequence, as a result of the redundancy or degeneracy of the genetic code, encodes the same mature enzyme as the DNA of Figures 1-6 SEQ ID NO:1).

The polynucleotide which encodes the mature enzyme of Figure 1 SEQ ID NO:1) may include, but is not limited to: only the coding sequence for the mature enzyme; the coding 30 sequence for the mature enzyme and additional coding sequence such as a leader sequence or a

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WO 99/07837 PCT/US98/17152 proprotein sequence: the coding sequence for the mature enzyme (and optionally additional coding sequence) and non-coding sequence. such as introns or non-coding sequence 5' and/or 3' of the coding sequence for the mature enzyme.

Thus. the term "polynucleotide encoding an enzyme (protein)" encompasses a polynucleotide which includes only coding sequence for the enzyme as well as a polynucleotide which includes additional coding and/or non-coding sequence.

The present invention further relates to variants of the hereinabove described polynucleotides which encode for fragments, analogs and derivatives of the enzyme having the deduced amino acid sequence of Figure 1 SEQ ID NO:2). The variant of the polynucleotide may be a naturally occurring allelic variant of the polynucleotide or a non-naturally occurring variant of the polynucleotide.

Thus. the present invention includes polynucleotides encoding the same mature enzyme as shown in Figure 1 as well as variants of such polynucleotides which variants encode for a fragment. derivative or analog of the enzyme of Figure 1. Such nucleotide variants include deletion variants, substitution variants and addition or insertion variants.

As hereinabove indicated, the polynucleotide may have a coding sequence which is a naturally occurring allelic variant of the coding sequence shown in Figure 1. As known in the art. an allelic variant is an alternate form of a polynucleotide sequence which may have. a 20 substitution. deletion or addition of one or more nucleotides, which does not substantially alter the function of the encoded enzyme.

The present invention also includes polynucleotides. wherein the coding sequence for the mature enzyme may be fused in the same reading frame to a polynucleotide sequence which aids in expression and secretion of an enzyme from a host cell. for example. a leader sequence which functions to control transport of an enzyme from the cell. The enzyme having a leader sequence is a preprotein and may have the leader sequence cleaved by the host cell to form the mature form of the enzyme. The polynucleotides may also encode for a proprotein which is the mature protein plus additional 5' amino acid residues. A mature protein having a prosequence is a proprotein and is an inactive form of the protein. Once the prosequence is cleaved an active 30 mature protein remains.

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WO 99/07837 PCT/US98/17152 Thus. for example, the polynucleotide of the present invention may encode for a mature enzyme. or for an enzyme having a prosequence or for an enzyme having both a prosequence and a presequence (leader sequence).

The present invention further relates to poivnucieotides which hybridize to the hereinabove-described sequences if there is at least 70%. preferably at least 90%. and more preferably at least 95% identity between the sequences. The present invention particularly relates to polynucleotides which hybridize under stringent conditions to the hereinabove-described polynucleotides. As herein used, the term "stringent conditions" means hybridization will occur only if there is at least 95% and preferably at least 97% identity between the sequences. The polynucleotides which hybridize to the hereinabove described polynucleotides in a preferred embodiment encode enzymes which either retain substantially the same biological function or activity as the mature enzyme encoded by the DNA of Figure 1.

Alternatively the polynucleotide may have at least 15 bases, preferably at least 30 bases, is and more preferably at least 50 bases which hybridize to a polynucleotide of the present invention and which has an identity thereto, as hereinabove described, and which may or may not retain activity. For example. such polynucleotides may be employed as probes for the polynucleotide of SEQ ID NO:1. for example, for recovery of the polynucleotide or as a PCR primer.

Thus, the present invention is directed to polynucleotides having at least a 70% identity, 20 preferably at least 90% identity and more preferably at least a 95% identity to a polynucleotide which encodes the enzyme of SEQ ID NO:1 as well as fragments thereof, which fragments have at least 30 bases and preferably at least 50 bases to enzymes encoded by such polynucleotides.

The present invention further relates to an enzyme which has the deduced amino acid sequence 'f Figures 1-6, as well as fragments. analogs and derivatives of such enzyme.

25 The terms "fragment" "derivative" and "analog" when referring to the enzyme of Figure I means a enzyme which retains essentially the same biological function or activity as such enzyme. Thus. an analog includes a .proprotein which can be activated by cleavage of the proprotein portion to produce an active mature enzyme.

The enzyme of the present invention may be a recombinant enzyme, a natural enzyme or 30 a synthetic enzyme. preferably a recombinant enzyme.

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WO 99/07837 PCT/US98/17152 The fragmcnt. derivative or analog of the enzyme of Figure 1 may be one in which one or more of the amino acid residues are substituted with a conserved or non-conserved amino acid residue (preferably a conserved amino acid residue) and such substituted amino acid residue s may or may not be one encoded by the genetic code. or (ii) one in which one or more of the amino acid residues includes a substiruent group. or (iii) one in which the mature enzyme is fused with another compound. such as a compound to increase the half-life of the enzyme (for example, polyethylene glycol). or (iv) one in which the additional amino acids are fused to the mature enzyme. such as a leader or secretory sequence or a sequence which is employed for purification to of the mature enzyme or a proprotein sequence. Such fragments. derivatives and analogs are deemed to be within the scope of those skilled in the art from the teachings herein.

The enzymes and polynucleotides of the present invention are preferably provided in an isolated form. and preferably are purified to homogeneity.

The term "isolated" means that the material is removed from its original environment is the natural environment if it is naturally occurring). For example, a naturally-occurring polynucleotide or enzyme present in a living animal is not isolated, but the same polynucleotide or enzyme. separated from some or all of the coexisting materials in the natural system, is isolated. Such polynucleotides could be part of a vector and/or such polynucleotides or enzymes could be part of a composition, and still be isolated in that such vector or composition is not part 20 of its natural environment.

The enzymes of the present invention include an enzyme of Figures 1-6 (in particular the mature enzyme) as well as enzymes which have at least 70% similarity (preferably at least identity) to an enzyme of Figures 1-6 and more preferably at least 90% similarity (more preferablfat least 90% identity) to an enzymes of Figures 1-6 and still more preferably at least 25 95% similarity (still more preferably at least 95% identity) to an enzyme of Figures 1-6 and also include portions of such enzymes with such portion of the. enzyme generally containing at least 30 amino acids and more preferably at least 50 amino acids.

As known in the art "similaritv" between two enzymes is determined by comparing the amino acid sequence and its conserved amino acid substitutes of one enzyme to the sequence of a second enzyme. Similarity in nucleic acid and amino acid sequences may be determined by S procedures and algorithms which are well-known in the art. Such procedures and algorithms

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WO 99/07837 PCT/US98/17152 include, for example. a BLAST program (Basic Local Alignment Search Tool at the National Center for Biological Information). ALIGN. AMAS (Analysis of Multiply Aligned Sequences).

AMPS (Protein Multiple Sequence Alignment). ASSET (Aligned Segment Statistical Evaluation Tool). BANDS. BESTSCOR. BIOSCAN (Biological Sequence Comparative Analysis Node).

BLIMPS (BLocks IMProved Searcher). FASTA. Intervals Points. BMB. -CLUSTAL V.

CLUSTAL W. CONSENSUS, LCONSENSUS. WCONSENSUS. Smith-Waterman algorithm.

DARWIN. Las Vegas algorithm, FNAT (Forced Nucleotide Alignment Tool). Framealign.

Framesearch, DYNAMIC, FILTER, FSAP (Fristensky Sequence Analysis Package). GAP (Global 1o Alignment Program), GENAL. GIBBS. GenQuest. ISSC (Sensitive Sequence Comparison).

LALIGN (Local Sequence Alignment). LCP (Local Content Program). MACAW (Multiple Alignment Construction Analysis Workbench). MAP (Multiple Alignment Program). MBLKP.

MBLKN, PIMA (Pattern-Induced Multi-sequence Alignment), SAGA (Sequence Alignmnet by Genetic ALgorithm) and WHAT-IF.

is A variant. i.e. a "fragment", "analog" or "derivative" enzyme. and reference enzyme may differ in amino acid sequence by one or more substitutions, additions. deletions. fusions and truncations, which may be present in any combination.

Among preferred variants are those that vary from a reference by conservative amino acid substitutions. Such substitutions are those that substitute a given amino acid in a polypeptide by 20 another amino acid of like characteristics. Typically seen as conservative substitutions are the replacements. one for another, among the aliphatic amino acids Ala. Val. Leu and lie: interchange of the hydroxyl residues Ser and Thr. exchange of the acidic residues Asp and Glu. substitution between the amide residues Asn and Gin, exchanee of the basic residues Lys and Arg and replacemnents among the aromatic residues Phe, Tyr.

25 Most highly preferred are variants which retain the same biological function and activity as the reference polypeptide from which it varies.

Fragments or portions of the enzymes of the present invention may be employed for producing the corresponding full-length enzyme by peptide synthesis: therefore. the fragments may be employed as intermediates for producing the full-length enzymes. Fragments or portions o 30 of the polynucleotides of the present invention may be used to synthesize full-length **polynucleotides of the present invention.

WO 99/07837 PCT/US98/17152 The present invention also relates to vectors which include polynucleotides of the present invention, host cells which are genetically engineered with vectors of the invention and the production of enzymes of the invention by recombinant techniques.

Host cells are genetically engineered (transduced or transformed or transfected) with the vectors containing the polynucleotides of this invention. Such vectors may be. for example, a cloning vector or an expression vector. The vector may be. for example. in the form of a plasmid. a viral particle, a phage, etc. The engineered host cells can be cultured in conventional nutrient media modified as appropriate for activating promoters, selecting transformants or amplifying the genes of the present invention. The culture conditions, such as temperature. pH and the like. are those previously used with the host cell selected for expression. and will be apparent to the ordinarily skilled artisan.

The polynucleotides of the present invention may be employed for producing enzymes by recombinant techniques. Thus, for example, the polynucleotide may be included in any one of a variety of expression vectors for expressing an enzyme. Such vectors include chromosomal.

nonchromosomal and synthetic DNA sequences, derivatives of SV40: bacterial plasmids: phage DNA; baculovirus; yeast plasmids; vectors derived from combinations of plasmids and phage DNA. viral DNA such as vaccinia, adenovirus. fowl pox virus, and pseudorabies.

However, any other vector may be used as long as it is replicable and viable in the host.

20 The appropriate DNA sequence may be inserted into the vector by a variety of procedures.

In general, the DNA sequence is inserted into an appropriate restriction endonuclease site(s) by procedures known in the art. Such procedures and others are deemed to be within the scope of those skilled in the art.

The DNA sequence in the expression vector is operatively linked to an appropriate 25 expression control sequence(s) (promoter) to direct mRNA synthesis. As representative examples of such promoters, there may be mentioned: LTR or SV40 promoter. the E. coli. lac or trp. the phage lambda PL promoter and other promoters known to control expression of genes in prokaryotic or eukaryotic cells or their viruses. The expression vector also contains a ribosome binding site for translation initiation and a transcription terminator. The vector may also include 30 appropriate sequences for amplifying expression.

WO 99/07837 PCT/US98/17152 In addition, the expression vectors preferably contain one or more selectable marker genes to provide a phenotypic trait for selection of transformed host cells such as dihydrofolate reductase or neomycin resistance for eukaryotic cell culture, or such as tetracycline or ampicillin resistance in E. coli.

The vector containing the appropriate DNA sequence as hereinabove described, as well as an appropriate promoter or control sequence. may be employed to transform an appropriate host to permit the host to express the protein.

As representative examples of appropriate hosts, there may be mentioned: bacterial cells.

1o such as E. coli. Streptomyces, Bacillus subtilis; fungal cells. such .as yeast: insect cells such as Drosophila S2 and Spodoptera Sf9: animal cells such as CHO. COS or Bowes melanoma: adenoviruses; plant cells. etc. The selection of an appropriate host is deemed to be within the scope of those skilled in the art from the teachings herein.

More particularly, the present invention also includes recombinant constructs comprising is one or more of the sequences as broadly described above. The constructs comprise a vector, such as a plasmid or viral vector. into which a sequence of the invention has been inserted, in a forward or reverse orientation. In a preferred aspect of this embodiment, the construct further comprises regulatory sequences, including, for example, a promoter. operably linked to the sequence. Large numbers of suitable vectors and promoters are known to those of skill in the 20 art, and are commercially available. The following vectors are provided by way of example; Bacterial: pQE70. pQE60. pQE-9 (Qiagen), pBluescript II (Stratagene): pTRC99a. pKK223-3.

pDR540. pRIT2T (Pharmacia); Eukarvotic: pXT1, pSG5 (Stratagene) pSVK3, pBPV pMSG.

e pSVLSV40 (Pharmacia). However, any other plasmid or vector may be used as long as they are replicabif and viable in the host.

Promoter regions can be selected from any desired gene using CAT -(chloramphenicol transferase) vectors or other vectors with selectable markers. Two appropriate vectors are pKK232-8 and pCM7. Particular named bacterial promoters include lad. lacZ, T3. T7, gpt.

lambda PR, P, and trp. Eukarvotic promoters include CMV immediate early. HSV thymidine kinase. early and late SV40, LTRs from retrovirus, and mouse metallothionein-I. Selection of 30 the appropriate vector and promoter is well within the level of ordinary skill in the art.

0505 WO 99/07837 PCT/US98/17152 In a further embodiment, the present invention relates to host cells containing the above-described constructs. The host cell can be a higher eukaryotic cell, such as a mammalian cell, or a lower eukaryotic cell, such as a yeast cell, or the host cell can be a prokaryotic cell, s such as a bacterial cell. introduction of the construct into the host cell can be effected by calcium phosphate transfection, DEAE-Dextran mediated transfection. or electroporation (Davis, L..

Dibner. Battey; Basic Methods in Molecular Biology, (1986)).

The constructs in host cells can be used in a conventional manner to produce the gene product encoded by the recombinant sequence. Alternatively, the enzymes of the invention can be synthetically produced by conventional peptide synthesizers.

Mature proteins can be expressed in mammalian cells, yeast bacteria, or other cells under the control of appropriate promoters. Cell-free translation systems can also be employed to produce such proteins using RNAs derived from the DNA constructs of the present invention.

Appropriate cloning and expression vectors for use with prokaryotic and eukaryotic hosts are described by Sambrook et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor, N.Y, (1989), the disclosure of which is hereby incorporated by reference.

Transcription of the DNA encoding the enzymes of the present invention by higher eukarvotes is increased by inserting an enhancer sequence into the vector. Enhancers are cis-acting elements of DNA, usually about from 10 to 300 bp that act on a promoter to increase 20 its transcription. Examples include the SV40 enhancer on the late side of the replication origin bp 100 to 270. a cytomegalovirus early promoter enhancer, the polyoma enhancer on the late side S of the replication origin, and adenovirus enhancers.

Generally recombinant expression vectors will include origins of replication and selectable markers phmitting transformation of the host cell, the ampicillin resistance gene of E. coli 25 and S. cerevisiae TRP1 gene, and a promoter derived from a highly-expressed gene to direct transcription of a downstream structural sequence. Such promoters can be derived from operons encoding glycolytic enzymes such as 3-phosphoglycerate kinase (PGK), a-factor. acid phosphatase, or heat shock proteins, among others. The heterologous structural sequence is assembled in appropriate phase with translation initiation and termination sequences, and preferably, a leader sequence capable of directing secretion of translated enzyme. Optionally. the WO 99/07837 PCT/US98/17152 heterologous sequencc can encode a fusion enzyme including an N-terminal identification pcptide imparting desired characteristics. stabilization or simplified purification of expressed recombinant product.

Useful expression vectors for bacterial use are constructed by insening a structural DNA sequence encoding a desired protein together with suitable translation initiation and termination signals in operable reading phase with a functional promoter. The vector will comprise one or more phenotypic selectable markers and an origin of replication to ensure maintenance of the vector and to, if desirable, provide amplification within the host. Suitable prokaryotic hosts for transformation include E. coli, Bacillus subtilis, Salmonella typhimurium and various species within the genera Pseudomonas. Streptomyces. and Staphylococcus, although others may also be employed as a matter of choice.

As a representative but nonlimiting example, useful expression vectors for bacterial use can comprise a selectable marker and bacterial origin of replication derived from commercially available plasmids comprising genetic elements of the well known cloning vector pBR322 (ATCC 37017). Such commercial vectors include, for example, pKK223-3 (Pharmacia Fine Chemicals, SUppsala. Sweden) and GEMI (Promega Biotec, Madison, WI, USA). These pBR322 "backbone" sections are combined with an appropriate promoter and the structural sequence to be expressed.

Following transformation of a suitable host strain and growth of the host strain to an i. 20 appropriate cell density the selected promoter is induced by appropriate means temperature shift or chemical induction) and cells are cultured for an additional period.

Cells are typically harvested by centrifugation, disrupted by physical or chemical means, and the resulting crude extract retained for further purification.

Mierobial cells employed in expression of proteins can be disrupted by any convenient 2S method, including freeze-thaw cycling, sonication, mechanical disruption, or use of cell lysing agents, such methods are well known to those skilled in the art.

Various mammalian cell culture systems can also be employed to express recombinant protein. Examples of mammalian expression systems include the COS-7 lines of monkey kidney fibroblasts. described by Gluzman, Cell 23:175 (1981), and other cell lines capable of expressing a compatible vector, for example, the C127, 3T3, CHO, HeLa and BHK cell lines. Mammalian expression vectors will comprise an origin of replication, a suitable promoter and enhancer, and WO 99/07837 PCT/US98/17152 also any necessary ribosome binding sites, polyadenylation site, splice donor and acceptor sites.

transcriptional termination sequences, and 5' flanking nontranscribed sequences. DNA sequences derived from the SV40 splice, and polyadenylation sites may be used to provide the required nontranscribed genetic elements.

The enzyme can be recovered and purified from recombinant cell cultures by methods including ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, affinity chromatography, hydroxylapatite chromatography and lectin chromatography. Protein refolding steps can be used, as necessary, in completing configuration of the mature protein.

Finally, high performance liquid chromatography (HPLC) can be employed for final purification steps.

The enzymes of the present invention may be a naturally purified product, or a product of chemical synthetic procedures, or produced by recombinant techniques from a prokaryotic or is eukaryotic host (for example, by bacterial, yeast, higher plant, insect and mammalian cells in culture). Depending upon the host employed in a recombinant production procedure. the enzymes of the present invention may be glycosylated or may be non-glycosylated. Enzymes of the invention may or may not also include an initial methionine amino acid residue.

The enzyme of this invention may be employed for any purpose in which such enzyme 20 activity is necessary or desired. In a preferred embodiment the enzyme is employed for catalyzing DNA synthesis by addition of deoxynucleotides to the 3' end of a polynucleotide chain, using a complementary polynucleotide strand as a template.

In a preferred embodiment, the enzyme of the present invention is-a thermostable enzyme which is"stable to heat and is heat resistant and polymerizes DNA, the enzyme is able to 25 renature and regain activity after a brief 5-to 30 seconds), or longerperiod for example, minutes or hours, exposure to temperatures of up to 70'C and has a temperature optimum above The enzymes, their fragments or other derivatives, or analogs thereof, or cells expressing them can be used as an immunogen to produce antibodies thereto. These antibodies can be, for example, polyclonal or monoclonal antibodies. The present invention also includes chimeric, single chain, and humanized antibodies, as well as Fab fragments, or the product of an Fab WO 99/07837 PCT/US98/17152 expression library. Various procedures known in the an may be used for the production of such antibodies and fragments.

Antibodies generated against the enzymes corresponding to a sequence of the present invention can be obtained by direct injection of the enzymes into an animal or by administerine the enzymes to an animal. preferably a nonhuman. The antibody so obtained will then bind the enzymes itself In this manner. even a sequence encoding only a fragment of the enzymes can be used to generate antibodies binding the whole native enzymes. Such antibodies can then be used to isolate the enzyme from cells expressing that enzyme.

For preparation of monoclonal antibodies, any technique which provides antibodies produced by continuous cell line cultures can be used. Examples include the hybridoma technique (Kohler and Milstein. 1975, Nature, 256:495-497), the trioma technique, the human B-cell hybridoma technique (Kozbor et al.. 1983, Immunology Today 4:72). and the EBV-hybridoma technique to produce human monoclonal antibodies (Cole, et al., 1985, in is Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc.. pp. 77-96).

Techniques described for the production of single chain antibodies Patent 4,946,778) can be adapted to produce single chain antibodies to immunogenic enzyme products of this invention. Also. transgenic mice may be used to express humanized antibodies to immunogenic enzyme products of this invention.

Antibodies generated against the enzyme of the present invention may be used in screening for similar enzymes from other organisms and samples. Such screening techniques are S known in the art. for example. one such screening assay is described in "Methods for Measuring Cellulase Activities". Methods in Enzywology, Vol 160, pp. 87-116. which is hereby incorporated by reference in its entirety. Antibodies may also be employed as a probe to screen gene libraries 25 generated from this or other organisms to identify this or cross reactive activities.

Isolation and purification of polypeptides produced in the systems described above can be carried out using conventional methods, appropriate for the particular system. For example.

preparative chromatography and immunological separations employing antibodies. such as monoclonal or polyclonal antibodies, can be used.

Tne term "antibody." as used herein, refers to intact immunoglobulin molecules, as well as fragments of immunoglobulin molecules, such as Fab. Fab', Fv. and SCA fragments.

WO 99/07837 PCT/US98/17152 that are capable of binding to an epitope of a polymerase polypeptide. These antibody fragments.

which retain some ability to selectively bind to the antigen a polymerase antigen) of the antibody from which they are derived, can be made using well known methods in the art (see.

Harlow and Lane. supra). and are described further, as follows.

A Fab fragment consists of a monovalent antigen-binding fragment of an antibody molecule, and can be produced by digestion of a whole antibody molecule with the enzyme papain, to yield a fragment consisting of an intact light chain and a portion of a heavy chain.

.o A Fab' fragment of an antibody molecule can be obtained by treating a whole antibody molecule with pepsin, followed by reduction. to yield a molecule consisting of an intact light chain and a portion of a heavy chain. Two Fab' fragments are obtained per antibody molecule treated in this manner.

A (Fab') fragment of an antibody can be obtained by treating a whole antibody molecule with the enzyme pepsin, without subsequent reduction. A (Fab'), fraement is a dimer of two Fab' fragments. held together by two disulfide bonds.

An Fv fragment is defined as a genetically engineered fragment containing the variable region of a light chain and the variable region of a heavy chain expressed as two chains.

A single chain antibody is a genetically engineered single chain molecule containing the variable region of a light chain and the variable region of a heavy chain, linked by a suitable, flexible polypeptide linker.

As used in this invention, the term "epitope" refers to an antigenic determinant on an antigen, such as a polymerase polypeptide, to which the paratope of an antibody, such as a polymerase-specific antibody, binds. Antigenic determinants usually consist of chemically active surface eroupings of molecules, such as amino acids or sugar side chains. and can have specific three-dimensional structural characteristics, as well as specific charge characteristics.

As is mentioned above, antigens that can be used in producing polymerase-specific.

antibodies include polymerase polypeptides, any of the polymerases shown in Figures 1-X polypeptide fragments. The polypeptide or peptide used to immunize an animal can be obtained by standard recombinant, chemical synthetic, or purification methods. As is well known in the

I

WO 99/07837 PCT/US98/17152 art, in order to increase immunogcnicity. an antigen can be conjugated to a carrier protein.

Commonly used carriers include keyhole limpet hemocyanin (KLH). thyroglobuiin. bovine serum albumin (BSA). and tetanus toxoid. The coupled peptide is then used to immunize the animal a mouse, a rat. or a rabbit). In addition to such carriers, well known adjuvants can be administered with the antigen to facilitate induction of a strong immune response.

Polymerase-specific polyclonal and monoclonal antibodies can be purified, for example.

by binding to, and elution from. a matrix containing a polymerase polypeptide. the polymerase polypeptide (or fragment thereof) to which the antibodies were raised. Additional methods for antibody purification and concentration are well known in the art and can be practiced with the polymerase-specific antibodies of the invention (see. for example. Coligan. et al.. Unit 9. Current Protocols in Immunology, Wiley Interscience. 1994).

Anti-idiotype antibodies corresponding to polymerase-specific antigens are also included in the invention, and can be produced using standard methods. These antibodies are raised to polymerase-specific antibodies, and thus mimic polymerase-specific epitopes.

The members of a pair of molecules an antibody-antigen pair or a nucleic acid pair) are said to "specifically bind" to each other if they bind to each other with greater affinity than to other. non-specific molecules. For example. an antibody raised against an antigen to which it binds more efficiently than to a non-specific protein can be described as specifically binding 20 to the antigen. (Similarly, a nucleic acid probe can be described as specifically binding to a nucleic acid target if it forms a specific duplex with the target by base pairing interactions (see above).) The present invention is further described with reference to the following examples; however, it is to be understood that the present invention is not limited to such examples. All 25 parts or amounts, unless otherwise specified, are by weight.

In one aspect of the invention, a method for producing a polymerase enzyme, such as those shown in Figures 1-6, is provided. The method includes growing a host cell which contains a polynucleotide encoding the enzyme SEQ ID Nos:2, 4. 6. 8. 10. 12). under conditions which allow the expression of the nucleic acid, and isolating the enzyme encoded by the nucleic acid. Methods of culturing the host cell are described in the Examples and are known by those of skill in the art.

WO 99/07837 PCT/US98/17152 In order to facilitate understanding of the following examples certain frequently occurring methods and/or terms will be described.

"Plasmids" are designated by a lower case p preceded and/or followed by capital letters and/or numbers. The starting plasmids herein are either commercially available. publicly available on an unrestricted basis. or can be constructed from available plasmids in accord with published procedures. In addition, equivalent plasmids to those described are known in the an and will be apparent to the ordinarily skilled artisan.

"Digestion" of DNA refers to catalytic cleavage of the DNA with a restriction enzyme that acts only at certain sequences in the DNA. The various restriction enzymes used herein are commercially available and their reaction conditions. cofactors and other requirements were used as would be known to the ordinarily skilled artisan. For analytical purposes, typically 1 ug of plasmid or DNA fragment is used with about 2 units of enzyme in about 20 pl of buffer solution.

For the purpose of isolating DNA fragments for plasmid construction, typically 5 to 50 ug of is DNA are digested with 20 to 250 units of enzyme in a larger volume. Appropriate buffers and substrate amounts for particular restriction enzymes are specified by the manufacturer. Incubation times of about 1 hour at 37'C are ordinarily used, but may vary in accordance with the supplier's instructions. After digestion the reaction is electrophoresed directly on a polyacrylamide gel to isolate the desired fragment.

Size separation of the cleaved fragments is generally performed using 8 percent polyacrylamide gel described by Goeddel, D. et al., Nucleic Acids Res.. 8:4057 (1980). for example.

"Oligonucleotides" refers to either a single stranded polydeoxynucleotide or two complementary polydeoxynucleotide strands which may be chemically synthesized. Such synthetic oligonucleotides may or may not have a 5' phosphate. Those that do not will not ligate to another oligonucleotide without adding a phosphate with an ATP in the presence of a kinase.

A synthetic oligonucleotide will ligate to a fragment that has not been dephosphorylated.

"Ligation" refers to the process of forming phosphodiester bonds between two double stranded nucleic acid fragments (Maniatis, et al., Id., p. 146). Unless otherwise provided.

ligation may be accomplished using known buffers and conditions with 10 units of T4 DNA WO 99/07837 PCT/US98/17152 ligase ("ligase") per 0.5 1g of approximately equimolar amounts of the DNA fragments to be ligated.

Unless otherwise stated, transformation was performed as described in the method of s Sambrook. Fritsch and Maniatis. 1989. The following examples are intended to illustrate, but not to limit the invention. While the procedures described in the examples are typical of those that can be used to carry out certain aspects of the invention, other procedures known to those skilled in the art can also be used. The following materials and methods were used in carrying out the experiments described in the examples.

e .e *a WO 99/07837 PCT/US98/17152 Example I DNA Isolation and Library Construction The following outlines the procedures used to generate a gene library from a sample.

Isolate DNA.

IsoQuick Procedure as per manufacturer's instructions (Orca, Research Inc.. Bothell. WA).

Shear DNA 1Vigorously push and pull DNA through a 25G double-hub needle and 1-cc syringes about 500 times.

Check a small amount (0.5 pg) on a 0.8% agarose gel to make sure the majority of the DNA is in the desired size range (about 3-6 kb).

Blunt DNA Add: H,O to a final volume of 405 ,pl 45 pl 10X Mung Bean Buffer 2.0 pl Mung Bean Nuclease (150 u/pl) 20 Incubate 37 0 C, 15 minutes.

Phenol/chloroform extract once.

Chloroform extract once.

Add 1 ml ice cold ethanol to precipitate.

Place on ice for 10 minutes.

25 Spin in microfuge, high speed, Wash with 1 ml 70% ethanol.

Spin in microfuge high speed, 10 minutes and dr Spin in microfuge, high speed, 10 minutes and dry.

WO 99/07837 WO 9907837PCT/US98/17152 Methylate DNA Gently resuspend DNA in 26 p.1 TE.

Add: 54.0 p1 1OX EcoR I Methylase Buffer [11 SAM (32 mM) P.1 EcoR I Methylase (40 u/pAI) Incubate 370, 1 hour.

Insure Blunt Ends Add to the methylation reaction: i.0 1.1 100 mM MgYCI, dNTP mix (2.5 mM of each dGTP, dATP. dTTP. dCTP) p1 Klenow (5 u4±l) Incubate 1 2'C, 30 minutes.

Add 450 pi1 I X STE.

Phenol/chloroformn extract once.

Chloroform extract once.

Add 1 ml ice cold ethanol to precipitate and place on ice for 10 minutes.

Spin in microfuge, high speed, 30 minutes.

20: M sh with I mnl70% ethanol.

Spin in microfuge. high speed. 10 minutes and- dry. Adaptor Ligation Getly resuspend DNA in 8 p 1 EcoR I adaptors (from Stratagene's cDNA Synthesis Kit).

.25 Add: 1.04p1 l OX Lig~ation Buffer P.1 10 mM rATP p.1 T4 DNA Ligase (4 u/p1) Incubate 4'C, 2 days.

I:

WO 99/07837 PCT/US98/17152 Phosphorylate Adaptors Heat kill ligation reaction 70 0 C, 30 minutes.

Add: 1.0 ip. 10X Ligation Buffer pl 10mM rATP ptl H,O pl Polynucleotide kinase (PNK) Incubate 37°C, 30 minutes.

o Add 31 p1 HO and 5 p 10X STE.

Size fractionate on a Sephacryl S-500 spin column (pool fractions 1-3).

Phenol/chloroform extract once.

Chloroform extract once.

Add ice cold ethanol to precipitate.

Place on ice, 10 minutes.

Spin in microfuge, high speed, 30 minutes.

Wash with 1 ml 70% ethanol.

Spin in microfuge, high speed. 10 minutes and dry.

Resuspend in 10.5 pl TE buffer.

20 Do not plate assay. Instead. ligate directly to arms as above except use 2.5 pi of DNA and no water.

Sucrose Gradient (2.2 ml) Size Fractionation Heat sample to 65C, 10 minutes.

Gently load on 2.2 ml sucrose gradient.

Spin in mini-ultracentrifuge, 45K, 20 0 C. 4 hours (no brake).

Collect fractions by puncturing the bottom of the gradient tube with a 20G needle and allowing the sucrose to flow through the needle. Collect the first 20 drops in a Falcon 2059 tube then collect 10 1-drop fractions (labelled 1-10). Each drop is about 60 p1 in volume.

Run 5 pl of each fraction on a 0.8% agarose gel to check the size.

WO 99/07837 PCTIUS98/17 152 Pool fractions 1-4 (about 10-1 .5 kb) and, in a separate tube, pool fractions 5-7 (about 5-0.5 kb).

Add I ml ice cold ethanol to precipitate and place on ice for 10 minutes.

Spin in microfuge. high speed. 30 minutes.

Wash with I ml 70% ethanol.

Spin in microfuge. high speed, 10 minutes and dry Resuspend each in 10 p1 TE buffer.

Test Ligation to Lambda Arms Plate assay to get an approximate concentration. Spot 0.5 p1 of the sample on agarose containine ethidium bromide along with standards (DNA samples of known concentration). V'iew in UV light and estimate concentration compared to the standards. Fraction 1 -4 >1.0 pg/pil.

Fraction 5-7 500 ng/pl.

Prepare the following ligation reactions (5 V.1 reactions) and incubate overnight: Sample H0lox lOMM% Lambd Insert T4 DNA Ligase rATP. a arms DNA Ligase (4 1Buffer (ZAP) U/111) Fraction 1-4 0.5pVl 0.5111 0.5pld 1.0p1l2.p1 Fraction 5-7 U.PI 0.5PI 0.5l p.11.PI 2.0p1 Test Package and Plate Package the ligation reactions following manufacturer's protocol- SW~g packaging reactions with 500 p1 SM buffer and pool packaging that came from the same ligzation.

Titer 1.0 p.1 of each on appropriate host (OD. 1.0) [XL -Blue MRF] Add 200 p.1 host (in mM MOW) to Falcon 2059 tubes Inoculate with I p1 packaged phage Incubate 3 7 0 C. 15 minutes Add about 3 m.l 48 0 C top ag~ar (S0ml stock containing 150 p.1 IPTG (0.5M) and 300 p.1 X-GAL- (350 mg/mI)] Plate on 100mm plates and incubate 37*C, overnight.

WO 99/07837 PCT/US98/17152 Amplification of Libraries (5.0 x 10' rccombinants from each library) Add 3.0 ml host cells (OD 6 to two 50 ml conical tube.

Inoculate with 2.5 X 10' pfu per conical tube.

Incubate 37°C. 20 minutes.

Add top agar to each tube to a final volume of 45 ml.

Plate the tube across five 150 mm plates.

Incubate 37°C. 6-8 hours or until plaques are about pin-head in size.

Overlay with 8-10 ml SM Buffer and place at 4°C overnight (with gentle rocking if possible).

Harvest Phage Recover phage suspension by pouring the SM buffer off each plate into a 50 ml conical tube.

Add 3 ml chloroform, shake vigorously and incubate at room temperature, 15 minutes.

Centrifuge at 2K rpm, 10 minutes to remove cell debris.

Pour supernatant into a sterile flask. add 500 pl chloroform.

Store at 4 0

C.

20 Titer Amplified Library Make serial dilutions: 10= 1 p.l amplified phage in 1 ml SM Buffer 106= 1 l of the 10' dilution in 1 ml SM Buffer Add 200 p.L host (in 10 mM MgSO,) to two tubes.

25 Inoculate one with 10 pl 10 6 dilution Inoculate the other with 1 I l 106 dilution (106).

Incubate 37 0 C, 15 minutes.

Add about 3 ml 48 0 C top agar.

stock containing 150 pil IPTG (0.5M) and 375 p.1 X-GAL (350 mg/ml)] Plate on 100 mm plates and incubate 37 0 C, overnight.

WO 99/07837 WO 9907837PCTIIJS98/1 7152 Excisc the ZAP 11 library to create thc pBlucscript library according to manufacturers protocols (Stratagene).

Strez Example 2 Actvatd alfThyusDNA Polym erase Assm, 0 0@ Soo s&* 0 0 0 too*S *600 ik out the clone to isolation: Inoculate 5mi LB/Amp/Meth/Kan culture with isolated clone Grow to turbidity Inoculate a 50mI culture of LB/Amp/MethlKan Grow to 0D600 of 0.7 to 0.9: induce culture w\ithi IPTG at a final concentration of 1mM for 3 hours Centrifuge at 4500 R.PM for 20 minutes and discard supernate Resuspend pellet in 3mls of 20mM Tris pH 8.0 and sonicate twice for 1 minute each Microcentrifugee Imi of sonicate, for 30 minutes at 4'C Remove I ul of the sonicate supernatent and add to I OfI of the following Activated Calf Thymus Reaction Cocktail in a 0.5m1 eppendorf: units/mi activated calf thymus DNA (Pharmacia 27-4575-01) ImnMDTT 40mg/ymi BSA 50uM dATP. 50uM dCTP, 5OuM dGTP. 5uM dTTP Tris pH 7.6 5mnM M2022 iCi/ml H--dTTP bring to volume with H20 Incubate at 70*C for 10-30 minutes Stop reaction by cooling the tube Spot sample onto Whatman DE-81 filter paper (cataloa,#3658-3)23)) Dry completely WAash filters in 2X SSC five times for 2 minutes each Final wash in 100% ethanol to remove most of remaining water WO 99/07837 PCT/UJS98/17 152 Allow the filters to dry to completion Count incorinoration of H ?-dTTP usinmi a scintillation counter T he incorporation of nucicoides by the polymerase is proportional to counts. by at least five fold over backeround. (MakI.H. et J.Biol.Chenn. (1988) 263:6570-6578 and Tabor. el al, US Patent 4795699).

Example 3 PCR Screening Polymerase sequences from Thermococcus litoralis. Pyrococcus GB-D (Deep \Vent).

and P%!rococcus furiosus were scanned to determine conserved regions. The following, nucleic ad sequences wvere identified and corresponding amino acid sequences were utilized to deriv'e degenerate oligonucleotide primers to be used in dowvnstream screening: Thermococcus litoralis: 37-45, 1045-1051 Pyrococcus GB-D (Deep Vent): 37-45, 1042-1049 Pvrococcus furiosus: 37-45. 505-512 The following corresponding amino acid sequences were used to produce deglenetate oligonucleotide primers: YIY.AkLLk/RDD WkAYc!SKECAE The primers hav'e been labeled Poldgenl forward and Poldgen.2 reverse: Poldgenl forward (26mer): Poldgen2 re verse (23mer): 5 -TCAfFGC/GCAc/TCcfFFIACAAk/GTACCA-3 These primers were used to amplify potential polymerase genes directly from genomic DNA (Template DNA).

-33- WO 99/07837 WO 9907837PCTIIUS98/17152 I O0jld PCR conditions: I p]l Poldegen]I forward (5O0n-s4± l) I [dl Poldgen2 reverse 41 d25mM dNTP mix I Template DNA O0ng/lil) I jal TaqPlus Polymerase (Stratagene) I Ojal I OX low salt reaction buffer (Stratagene)

H..O

Number of Temperature Time Cycles 0 C 30 seconds 42 0 C 30 seconds 72 0 C 2 minutes, seconds 95 C 30 seconds 500C 30 seconds 72 0 C 2 minutes,. seconds I )2C 10 minutes PCR products (1.4kb bands from both organisms) were phenol chloroform extracted (ref. Maniatis) and cloned using'the TA cloning system into th' GemT PCR Cloning Vector (Promega) using the following ligation reaction: 0.5 p.1 pGemT Cloning Vector 2[L PCR Product OO0ng4±l) 41I rATP 1I lOX T4 Ligase Buffer 1[.11 T4 Ligase 12.5Vp. H,O Incubate 4'C overnight.

WO 99/07837 PCT/US98/17152 2.51l of the above reaction was transformed into XLI-Blue MRF' competent cells (Stratagene) 1.4kb PCR products were also restriction analyzed using the appropriate restriction enzymes: Potential clones were verified by restriction analysis and sequenced.

BLASTX and BLASTN database comparisons of the sequences indicated whether the sequences were homologous to the nucleic acid sequence of a known polymerase from another organism. Amplification primers were then generated to both ends of the known polymerase gene, and were used in an amplification reaction on the genomic DNA in an attempt to pull out a full length polymerase gene from this organism. These primers include restriction sites and a new Ribosome Binding Site for downstream processing of the gene: PCR Conditions: 1s 11p forward primer (250ng/p.l) 1.1 reverse primer (250ng/ll) lIl 25mM dNTP ll template DNA (100ng/ll) 2. lI1l Taq polymerase 10l 1 0X Taq Buffer 85l H, WO 99/07837 PCT/US98/17152 r Number of Temperature Time Cycles 2 95°C 30 seconds 42 0 C 30 seconds 72 0 C 2 minutes. seconds 95 0 C 30 seconds 0 C 30 seconds 72 0 C 2 minutes. seconds GENE LIBRARY SCREENING PCR products generated in the above reactions (using degenerate primers) were used to make long "run off' single stranded DNA probes using (P 32 as a label).

The genomic library was screened using the single stranded (P 3 2 labeled probe.

Hybridization conditions for these screenings were as per Maniatis (maximum stringency for aqueous solutions; 68 C in rolling hybridization chamber).

All positive clones were then excised into pBluescript SK and sequenced.

Example 4 Expression Positive clones were identified and isolated from the genomic library by the above methods. DNA from the clones were then used as templates in a 100 ul PCR reaction. DNA encoding the enzymes of the present invention were initially amplified from a pBluescript vector containing the DNA by the PCR technique. The amplified sequences were then inserted into a PQE vector and the enzyme was expressed according to the protocols set forth herein.

The pQE vector (Qiagen, Inc. Chatsworth. CA) encodes antibiotic resistance a bacterial origin of replication (ori), an IPTG-regulatable promoter operator a ribosome binding site (RBS). a 6-His tag and restriction enzyme sites.

The pQE vector was digested with the appropriate restriction enzymes. The amplified sequences were ligated into the respective pQE vector and inserted in frame with the sequence

II

WO 99/07837 PCT/US98/17152 encoding for the RBS. The ligation mixture was then used to transform the E. coli strain M15/pREP4 (Qiagen. Inc.) by electroporation. M 5/pREP4 contains multiple copies of the plasmid pREP4. which expresses the lacl repressor and also confers kanamycin resistance (Kan').

Transformants were identified by their ability to grow on LB plates and ampicillin/kanamycin resistant colonies were selected. Plasmid DNA was isolated and confirmed by restriction analysis. Clones containing the desired constructs were grown overnight in liquid culture in LB media supplemented with both Amp (100 pg/ml) and Kan (25 pg/ml). The O/N culture was used to inoculate a large culture at a ratio of 1:100 to 1:250. The cells were grown to an optical density 600 of between 0.4 and 0.6. IPTG ("Isopropyl-B-D-thiogalacto pyranoside") was then added to a final concentration of 1 mlM. IPTG induces by inactivating the lacI repressor, clearing the P/O leading to increased gene expression. Cells were grown an extra 3 to 4 hours. Cells were then harvested by centrifugation.

Numerous modifications and variations of the present invention are possible in light of is the above teachings and, therefore, within the scope of the appended claims, the invention may be practiced otherwise than as particularly described. It is to be understood that, while the invention has been described with reference to the above detailed description, the foregoing description is intended to illustrate, but not to limit, the scope of the invention. Other aspects, S advantages, and modifications of the invention are within the scope of the following claims. All publications, patent applications, patents, and other referenced mentioned herein are incorporated by reference in their entirety.

004597510 It is to be understood that a reference herein to a prior art document does not constitute an admission that the document forms part of the common general knowledge in the art in Australia or in any other country.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" and grammatical variations thereof, is used in the sense of "including" i.e. the features specified may be associated with further features in various' embodiments of the invention.

o 0 o 37A

Claims (43)

1. An isolated or recombinant nucleic acid encoding a polymerase having (a) at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12; or, at least 30, 50, 100 or 150 consecutive amino acid residues of the sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of

2. An isolated or recombinant nucleic acid of claim 1, wherein the nucleic acid encodes a polymerase having at least 90%, 95% or 97% sequence identity to an amino acid sequence as set forth in SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO:8, SEQ ID NO: 10 or SEQ ID NO: 12.

3. An isolated or recombinant nucleic acid encoding a polymerase, wherein the nucleic acid comprises a sequence having at least 70% nucleic acid sequence identity to o* a nucleic acid sequence as set forth in SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5, SEQ 15 ID NO:7, SEQ ID NO:9, or SEQ ID NO:11; or, at least 30, 50, 100 or 150 consecutive bases of the sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of

4. An isolated or recombinant nucleic acid of claim 3, wherein the nucleic acid has at least 90%, 95% or 97% sequence identity to a nucleic acid sequence as set forth in 20 SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 9 or SEQ ID NO: 11.

5. An isolated or recombinant nucleic acid encoding a polymerase, wherein the nucleic acid comprises a sequence that hybridizes to a nucleic acid sequence as set forth in SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, or SEQ ID NO:11, wherein the hybridization conditions comprise a wash for 30 minutes at room temperature in a buffer comprising 150 mM NaC1, 20 mM Tris hydrochloride, pH 7.8, 1 mM Na 2 EDTA, containing 0.5% SDS, followed by a 30 minute wash in fresh buffer at 0 C, wherein the nucleic acid encodes enzymes which retain substantially the same biological function or activity as the mature enzyme encoded by the nucleic acid sequence as set forth in SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: III.IIYYLI.IIVI i 9 and SEQ ID NO: 11.

6. A vector comprising chromosomal, nonchromosomal or synthetic DNA, wherein the vector comprises a nucleic acid according to any one of the preceding claims.

7. A vector according to claim 6 comprising derivatives of SV40, bacterial plasmids, phage DNA, baculovirus, yeast plasmids, vaccinia, adenovirus, fowl pox virus, or pseudorabies.

8. A vector according to any one of the preceding claims, wherein the nucleic acid is operatively linked to a promoter comprising an LTR, an SV40 promoter, an E. coli promoter, a lac promoter, a trp promoter, a phage lambda PL promoter, lacI, lacZ, T3, T7, gpt, lambda PR, PL, trp, CMV immediate early, HSV thymidine kinase, early SV40, late LTR from retrovirus, or mouse metallothionein-I.

9. A vector according to any one of the preceding claims, further comprising a ribosome binding site, a polyadenylation site, a splice donor, an acceptor site, a transcriptional termination sequence, a 5' flanking nontranscribed sequence or a selectable 15 marker gene.

10. A vector of claim 9, wherein the selectable marker gene provides a phenotypic trait for selection of transformed host cells.

11. A vector of claim 10, wherein the selectable marker gene provides for dihydrofolate reductase or neomycin resistance in eukaryotic cell culture, or, tetracycline 20 or ampicillin resistance in E. coli.

12. A vector according to any one of the preceding claims, wherein the vector comprises pKK232-8, pCM7, pQE70, pQE60, pQE-9, pBluescript II, pTRC99a, pKK223- S: 3, pDR540, pRIT2T, pXT, pSG5, pSVK3, pBPV, pMSG or

13. A host cell comprising a nucleic acid or vector according to any one of the preceding claims, wherein the cell is a bacterial cell, a fungal cell, a yeast cell, an insect cell, an animal cell or a plant cell.

14. A host cell of claim 13, wherein the cell is E. coli, Streptomyces, Bacillus subtilis, Drosophila S2, Spodoptera Sf9i, CHO cells, COS cells, Bowes melanoma or adenovirus.

15. An isolated or recombinant polymerase having at least 70% amino acid I.lmYYYIUnl.YI sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12; or, at least 30, 100 or 150 consecutive amino acid residues of the sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of

16. An isolated or recombinant polymerase having an amino acid sequence that is a variant of an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, wherein the variant comprises an amino acid sequence having one or more substitutions, additions, deletions, fusions, truncations, or any combination thereof, which retains essentially the same biological function or activity as the amino acid sequence from which it varies; or, at least 30, 50, 100 or 150 consecutive amino acid residues of the sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of

17. An isolated or recombinant polymerase having a sequence that is a variant of an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, wherein the variant differs from S SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12 by one or more conservative amino acid substitutions, which retains essentially the S 20 same biological function or activity as the amino acid sequence from which it varies; or, at least 30, 50, 100 or 150 consecutive amino acid residues of the sequence of wherein said consecutive amino acid residues retain at least one polymerase specific- activity or epitope of the sequence of

18. An isolated or recombinant polymerase of claim 17, wherein the 25 conservative substitution comprises replacements, one for another, among the aliphatic amino acids Ala, Val, Leu and Ile; interchange of the hydroxyl residues Ser and Thr; exchange of the acidic residues Asp and Glu; substitution between the amide residues Asn and Gin; exchange of the basic residues Lys and Arg; replacements among the aromatic residues Phe, Tyr; or any combination thereof.

19. An isolated or recombinant polymerase of claim 16 or claim 17, wherein the polymerase has the same activity as the sequence from which it was derived. CYYY.O~Y~OII An isolated or recombinant polymerase of claim 16 or claim 17, wherein the polymerase has an activity different from the sequence from which it was derived.

21. An isolated or recombinant polymerase of claim 20, wherein the polymerase retains at least one polymerase-specific activity or a polymerase-specific epitope.

22. An isolated or recombinant polypeptide or peptide immunogen comprising a sequence of a polymerase according to any one of the preceding claims.

23. An isolated or recombinant polymerase according to any one of the preceding claims, further comprising a leader sequence, a secretory sequence or a proprotein sequence.

24. An isolated or recombinant polymerase according to any one of the preceding claims, further comprising polyethylene glycol. An isolated or recombinant polymerase according to any one of the preceding claims, wherein the polymerase is glycosylated or non-glycosylated. An isolated or recombinant polymerase according to any one of the 15 preceding claims, wherein the polymerase does not include an initial methionine amino acid residue.

27. An isolated or recombinant polymerase according to any one of the preceding claims, wherein the polymerase activity is thermostable.

28. An isolated or recombinant polymerase of claim 27, wherein the polymerase 20 is able to renature and regain activity after a 5 to 30 second, or longer, exposure to temperatures of up to 70 0 C, and has a temperature optimum above

29. An immunoassay kit comprising a polymerase according to any one of the preceding claims. Use of an isolated or recombinant polypeptide or peptide immunogen comprising a sequence of a polymerase according to any one of the preceding claims in an immunoassay.

31. A method for synthesizing a nucleic acid comprising the following steps: providing a polymerase having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive nucleotide residues of a sequence of providing a template nucleic acid; contacting the polymerase of with the nucleic acid of under conditions wherin the polymerase catalyzes synthesis of a nucleic acid.

32. A method according to claim 31, wherein the reaction of is a polymerase chain reaction (PCR).

33. Use of a polymerase having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, a sequence at least 30, 50, 100 or 150 consecutive amino acid residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of in a polymerase chain reaction (PCR). S: 34. A method for identifying a nucleic acid encoding a polymerase comprising 15 the following steps: *o S* providing a nucleic acid encoding a polymerase having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a nucleic acid comprising at least 10, 12, 15, 20, 25, 30, 35, 50, 100 or 150 consecutive amino acid ;00 20 residues of the sequence of wherein said nucleic acid corresponds to a polymerase- 0.0 conserved sequence as found in SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10 or SEQ ID NO: 12; providing a sample; using the nucleic acid of in a hybridization or a PCR reaction to identify a nucleic acid encoding a polymerase in the sample of(b). A method according to claim 34, wherein the sample comprises a nucleic acid library.

36. A method according to claim 34, wherein the sample comprises an organism.

37. A method for making a polymerase-specific antibody comprising the following steps: providing a polypeptide or peptide having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive amino acid residues of a sequence of and immunizing a non-human animal with the polypeptide or peptide of in an amount sufficient to generate an immune response in the non-human animal, thereby making a polymerase-specific antibody.

38. A method according to claim 37, further comprising isolating or purifying I the antibody. o• 15 39. A method according to claim 38, wherein purifying the antibody comprises binding to, and elution from, a matrix containing a polymerase polypeptide. A method according to claim 38, wherein the antibody comprises a polyclonal antibody or a monoclonal antibody.

41. An anti-idiotype antibody that specifically binds to a polymerase-specific 20 antibody, wherein the polymerase-specific antibody specifically binds a polypeptide or peptide having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive base residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific activity or epitope of the sequence of(i).

42. A single-chain polymerase-specific antibody that specifically binds to a polypeptide or peptide having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 IllnY Yl~nllVI consecutive base residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of(i).

43. A humanized polymerase-specific antibody that specifically binds to a polypeptide or peptide having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive base residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of

44. A chimeric polymerase-specific antibody that specifically binds to a polypeptide or peptide having at least 70% amino acid sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive base residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of 15 45. An isolated or recombinant polymerase according to any one of the preceding claims, wherein the polymerase is isolated or purified by methods comprising ammonium sulfate, ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, affinity chromatography, hydroxylapatite chromatography, lectin 20 chromatography, high performance liquid chromatography (HPLC) or any combination g: thereof.

46. A method for making a recombinant polymerase comprising the following .g steps: providing a nucleic acid encoding a polymerase having at least 70% amino acid 0 sequence identity to an amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, or SEQ ID NO:12, or, (ii) a sequence at least 30, 50, 100 or 150 consecutive base residues of a sequence of wherein said consecutive amino acid residues retain at least one polymerase specific-activity or epitope of the sequence of(i); and ~nlYLnnlU*.XYI expressing the nucleic acid, thereby making a recombinant polymerase.

47. A method according to claim 46, wherein the nucleic acid further comprises an expression vector.

48. A method according to claim 46, wherein the nucleic acid is expressed in a host cell.

49. A method according to claim 48, wherein the host cell is a mammalian host cell. A method according to claim 49, wherein the mammalian host cell comprises a COS-7 cell line, a monkey kidney fibroblast cell line, a C127 cell line, a 3T3 cell line, a CHO, cell line, a HeLa cell line or a BHK cell line.

51. An isolated or recombinant polymerase substantially as described herein with reference to the accompanying Figures.

52. An isolated or recombinant nucleic acid that encodes a polymerase according to claim 51. S 15 53. A vector comprising a nucleic acid according to claim 52. o 54. A cell comprising a molecule according to one of claims 51 to 53. Use of a polymerase of claim 51 for the synthesis of a nucleic acid. 0O*

56. An antibody for binding to a polymerase according to claim 51. 20 Diversa Corporation By its Registered Patent Attorneys Freehills Carter Smith Beadle 3 June 2004