Thermostable DNA polymerase

Last updated
Taq-DNA-Polymerase with exonuclease- (top left) and polymerase domain with DNA (bottom right) Taq.png
Taq-DNA-Polymerase with exonuclease- (top left) and polymerase domain with DNA (bottom right)

Thermostable DNA polymerases are DNA polymerases that originate from thermophiles, usually bacterial or archaeal species, and are therefore thermostable. They are used for the polymerase chain reaction and related methods for the amplification and modification of DNA.

Contents

Properties

Several DNA polymerases have been described with distinct properties that define their specific utilisation in a PCR, in real-time PCR or in an isothermal amplification. Being DNA polymerases, the thermostable DNA polymerases all have a 5'→3' polymerase activity, and either a 5'→3' or a 3'→5' exonuclease activity.

Properties of thermostable DNA polymerases
PolymeraseTaqTflTthBst Klenow fragment (BF),
strand displacing
Tli (Vent)P GB-D (Deep Vent)Pfx (KOD)Pfu
Organism Thermus aquaticus Thermus flavus Thermus thermophilus Geobacillus stearothermophilus Thermococcus litoralis Pyrococcus sp. strain GB-D Pyrococcus kodakarensis Pyrococcus furiosus
Originbacterialbacterialbacterialbacterialarchaealarchaealarchaealarchaeal
Molecular weight80kDa [1] 94kDa [1] 94kDa [1] 67kDa [2] 90kDa [1] 90kDa [3] 90kDa [3] 92kDa [1]
Extension Temperature74 °C [1] 74 °C [1] 74 °C [1] 65 °C [2] 74 °C [1] 75 °C [3] 75 °C [3] 75 °C [1]
5′→3′ Exonuclease ActivityYes [1] Yes [1] Yes [1] No [2] No [1] No [1]
3′→5′ Exonuclease ActivityNo [1] No [1] No [1] No [2] Yes [1] Yes [3] Yes [3] Yes [1]
Reverse Transcriptase ActivityWeak [1] Yes [1] Yes [1] Weak [2] No [1] N/A [1]
PCR Ends3′-A [1] 3′-A [1] 3′-A [1] 3′-A [2] 70% Blunt; 30% Single-base [1] Blunt [3] Blunt [3] Blunt [1]
Fidelity (errors per base and doubling)8 × 10−6 [4]
1.5 × 10−4 [5]
3-5.6 × 10−5 [6]
1.5 × 10−5 [7] 2.8 × 10−6 [4] 2.7 × 10−6 [4]
4.0 × 10−6 [5]
3.5 × 10−6 [8]
1.2 × 10−5 [5]
7.6 × 10−6 [6]
1.3 × 10−6 [9] [4]
5.1 × 10−6 [5]
2.8 × 10−6 [6]
Synthesis rate (bases/sec.)21–47 [2]
61 [10]
191 [2] 23 [10] 120 [11]
106–138 [10]
9.3–25 [10]
Processivity (bases)10–42 [10] <20 [10] >300 [10] 6.4–20 [10]

Structure

DNA polymerases are roughly shaped like a hand with a thumb, palm and fingers. [12] [13] The thumb is involved in binding and moving double-stranded DNA. [12] The palm carries the polymerase active site, whereas the fingers bind substrates (template DNA and nucleoside triphosphates). [12] [14] The exonuclease activity is in a separate protein domain. [12] Mg2+ is a cofactor.

The polymerase active site in the palm catalyses the prolongation of DNA, starting from a primer bound to a template DNA single strand:

deoxynucleoside triphosphate + DNAn pyrophosphate + DNAn+1.

Bacterial polymerases

Thermostable DNA polymerases of natural origin are found in thermophilic bacteria, archaea and their pathogens. Among the bacterial thermostable DNA polymerases, Taq polymerase, Tfl polymerase, Tma polymerase, Tne polymerase, Tth and Bst polymerase are used. [4] [15] [16] [2]

In addition to 5'→3' polymerase activity, the bacterial thermostable DNA polymerases (belonging to the A-type DNA polymerases) have 5'→3' exonuclease activity and generate an adenosine overhang (sticky ends) at the 3' end of the newly generated strand. The Klenow fragment of Bst (BF) has a strand displacement activity which allows for use in isothermal amplification without the necessity of denaturation of the DNA in a thermocycler, and its 5'→3' exonuclease activity is deleted for higher yield. [2]

Archaeal polymerases

Pfu polymerase with two magnesium ions (grey spheres) Pfu Polymerase ribbon diagram.jpg
Pfu polymerase with two magnesium ions (grey spheres)

Frequently used B-type DNA polymerases are the Pfu polymerase, [4] the Pwo polymerase, [17] the KOD polymerase, [3] the Tli polymerase (also called Vent), which originates from various archaea, [18] the Tag polymerase, [19] the Tce polymerase, [20] the Tgo polymerase, [8] the TNA1 polymerase, [21] the Tpe polymerase, [22] the Tthi polymerase, [23] the Neq polymerase [24] and the Pab polymerase. [25]

The archaeal variants (belonging to the B-type) produce blunt ends (the Tli polymerase produces an overhang in about 30% of the products) and instead of the 5'→3' exonuclease activity have an activity for correcting synthesis errors (proof-reading), the 3'→5' exonuclease activity. [26] [27] In archaeal polymerases, the error rate suffers when a Klenow fragment analogue is generated, as the correcting exonuclease activity is removed in the process. [4] Some archaeal DNA polymerases are characterised less by their suitability for standard PCR than by their reduced inhibition in the amplification of A-DNA [28] or DNA with modified bases. [29] [30]

Modified polymerases

Various fusion proteins with the low error rate of archaeal and the high synthesis rate of bacterial thermostable DNA polymerases (Q5 polymerase) were generated from various thermostable polymerases and the DNA clamp of the thermostable DNA-binding protein SSo7d by protein design. [31] A fusion protein of the PCNA homologue from Archaeoglobus fulgidus was also generated with archaeal thermostable DNA polymerases. [32] Similarly, fusion proteins of thermostable DNA polymerases with the thermostable DNA-binding protein domain of a topoisomerase (type V, with helix-hairpin-helix motif, HhH) from Methanopyrus kandleri were generated (TopoTaq and PfuC2). [33] [34] A modified Pfu polymerase was also generated by protein design (Pfu Ultra). [35] Similar effects are also achieved with mixtures of thermostable DNA polymerases of both types with a mixing ratio of the enzyme activities of type A and B polymerases of 30 to 1, [22] [36] e.g. Herculase [8] and TaqPlus [10] as a commercial mixture of Taq and Pfu polymerase, Expand as a commercial mixture of Taq and Pwo, [37] Expand High Fidelity as a commercial mixture of Taq and Tgo, [10] Platinum Taq High Fidelity as a commercial mixture of Taq and Tli (Vent), [10] and Advantage HF 2 as a commercial mixture of Titanium Taq and an unnamed proof-reading polymerase. [10] These mixtures can be used for long-range PCR to synthesize products of up to 35kb length. [36] [38] Other additives are used to help against difficult G C-rich sequences, avoid or neutralise the negative effects of PCR inhibitors (like blood components or detergents [39] or dUTP [40] ), or alter the reaction kinetics. [41]

Speed & Processivity

The baseline synthesis rates (speed, productivity) of various polymerases have been compared. [8] The synthesis rate of Taq polymerase is around 60 base pairs per second. Among the unmodified thermostable DNA polymerases, only the synthesis rate of KOD polymerase is above 100 base pairs per second (approx. 120 bp/s). [11] Among the modified thermostable DNA polymerases, various mutations have been described that increase the synthesis rate. [42] [43] [44] KOD polymerase and some modified thermostable DNA polymerases (iProof/Phusion, Pfu Ultra, Velocity or Z-Taq) are used as a PCR variant with shorter amplification cycles (fast PCR, high-speed PCR) due to their high synthesis rate. Processivity describes the average number of base pairs before a polymerase falls off the DNA template. The processivity of the polymerase limits the maximum distance between the primer and the probe in some forms of real-time quantitative PCR (qPCR).

Fidelity

The error rates of various polymerases (fidelity) have been described. The error rate of Taq polymerase is 8 × 10−6 errors per base, that of Advantage HF 6.1 × 10−6 errors per base, that of Platinum Taq High Fidelity 5.8 × 10−6 errors per base and doubling, that of TaqPlus 4 × 10−6 errors per base and doubling, that of KOD polymerase 3.5 × 10−6 errors per base and doubling, that of Tli polymerase and Herculase 2.8 × 10−6 errors per base and doubling, that of Deep Vent 2.8 × 10−6 errors per base and doubling, that of Pfu, Phusion DNA Polymerase (identical with iProof DNA Polymerase) and Herculase II Fusion 1.3 × 10−6 errors per base and doubling and that of Pfu Ultra and Pfu Ultra II 4.3 × 10−7 errors per base and doubling. [4] [8] [10] A newer analysis found slightly different error rates: Deep Vent (exo-) polymerase (5.0 × 10−4 errors per base and doubling), Taq polymerase (1.5 × 10−4 errors per base and doubling), Kapa HiFi HotStart ReadyMix (1.6 × 10−5 errors per base and doubling), KOD (1.2 × 10−5 errors per base and doubling), PrimeSTAR GXL (8.4 × 10−6 errors per base and doubling), Pfu (5.1 × 10−6 errors per base and doubling), Deep Vent DNA polymerase (4.0 × 10−6) errors per base and doubling, Phusion (3.9 × 10−6 errors per base and doubling), and Q5 DNA polymerase (5.3 × 10−7 errors per base and doubling). [5] Yet another found error rates of 3-5.6 × 10−6 for Taq, 7.6 × 10−6 for KOD, 2.8 × 10−6 for Pfu, 2.6 × 10−6 for Phusion, and 2.4 × 10−6 for Pwo. [6] To reduce the number of mutations in the PCR product (e.g. for molecular cloning), more template DNA and less cycles can be used in the PCR. [10]

Yield

Bacterial thermostable DNA polymerases generally produce higher product concentrations than archaeal, but with more copy errors. In the bacterial thermostable DNA polymerases, a Klenow fragment (Klen-Taq) or a Stoffel fragment can be generated by deleting the exonuclease domain in the course of protein design, analogous to the DNA polymerase from E. coli, which results in a higher product concentration. [45] [15] Two amino acids required for the exonuclease function of Taq polymerase were identified by mutagenesis as arginines at positions 25 and 74 (R25 and R74). [46] A histidine to glutamic acid mutation at position 147 (short: H147E) in KOD polymerase lowers the relatively high exonuclease activity of KOD. [27]

Nucleotide specificity

The favouring of individual nucleotides by a thermostable DNA polymerase is referred to as nucleotide specificity (bias). In PCR-based DNA sequencing with chain termination substrates (dideoxy method), their uniform incorporation and thus unbiased generation of all chain termination products is often desired in order to enable higher sensitivity and easier analysis. For this purpose, a KlenTaq polymerase was generated by deletion and a phenylalanine at position 667 was exchanged for tyrosine by site-directed mutagenesis (short: F667Y) and named Thermo Sequenase. [47] [48] This polymerase can also be used for the incorporation of fluorescence-labelled dideoxynucleotides. [49]

Hot-start thermostable DNA polymerases

The template specificity of the polymerases is increased by using hot-start polymerases, to avoid binding of primers to unwanted DNA templates or to each other at low temperatures before the beginning of the PCR. [50] Examples are the antibody-inhibited Pfu polymerase Pfu Turbo, the Platinum Pfx as a commercial KOD polymerase with an inhibiting antibody and the Platinum Taq as an antibody-inhibited Taq polymerase. [8] Hot-start polymerases are either inhibited by inactivation with formaldehyde [51] [52] (or maleic anhydride, exo-cis-3,6-endoxo-Δ4-tetrahydropthalic anhydride, citraconic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, cis-aconitic anhydride, or 2,3-dimethylmaleic anhydride), [53] by complexing the magnesium with phosphates [54] or by binding an antibody to their active site. [55] [56] Upon heating to 95 °C, the formaldehyde dissociates from proteins, [57] [58] [59] or the magnesium ions are released, [54] or the antibody is denatured and released in the process. [60] [61] Furthermore, polymerases can be inhibited with aptamers that denature upon heating. [62] [63] A fifth variant is a polymerase adsorbed on latex beads via hydrophobic effects, which dissolves with increasing temperature. In the sixth and oldest variant, the reaction mixture without polymerase is coated with wax and the polymerase is added on top of the cooled wax. When heated, the wax layer melts and the polymerase mixes with the reaction mixture. [64]

Other DNA polymerases

Some DNA polymerases used in isothermal DNA amplification, e.g. in loop-mediated isothermal amplification, multidisplacement amplification, recombinase polymerase amplification or isothermal assembly, for the amplification of entire genomes (e.g. the φ29 DNA polymerase from the bacteriophage phi29, B35DNAP from the phage Bam35) are not thermostable, while others like the Bst Klenow fragment are thermostable. [65] The T4, T6 and T7 DNA polymerases are also not thermostable.

RNA-dependent DNA polymerases

The standard reverse transcriptases (RNA-dependent DNA polymerases) of retroviral origin used for RT-PCR, like the AMV- and the MoMuLV-Reverse-Transcriptase, are not thermostable at 95 °C. At the lower temperatures of a reverse transcription unspecific hybridisation of primers to wrong sequences can occur, as well as unwanted secondary structures in the DNA template, which can lead to unwanted PCR products and less desired PCR products. The AMV reverse transcriptase may be used up to 70 °C. [66] Also, some thermostable DNA-dependent DNA polymerases can be used as RNA-dependent DNA polymerases by exchanging Mg2+ as cofactors with Mn2+, so that they may be used for an RT-PCR. [67] But since the synthesis rate of Taq with Mn2+ is relatively low, Tth was increasingly used for this approach. [68] The use of Mn2+ also increases the error rate and the necessary amount of template, so that this method is rarely used. These problems can be avoided with the thermostable 3173-Polymerase from a thermophilic bacteriophage, which can withstand the high temperatures of a PCR and prefers RNA as a template. [69]

Applications

In addition to the choice of thermostable DNA polymerase, other parameters of a PCR are specifically changed in the course of PCR optimisation.

In addition to PCR, thermostable DNA polymerases are also used for RT-PCR variants, qPCR in different variants, site-specific mutagenesis and DNA sequencing. They are also used to produce hybridisation probes for Southern blot and Northern blot by random priming. The 5'→3' exonuclease activity is used for nick translation and TaqMan, among other things, without DNA replication (amplification).

History

Alice Chien and colleagues were the first to characterise the thermostable Taq polymerase in 1976. [70] The first use of a thermostable DNA polymerase was by Randall K. Saiki and colleagues in 1988, introducing Taq polymerase for PCR. [71] [72] The thermostability of Taq polymerase obliviated the need to add a non-thermostable DNA polymerase to the reaction after every melting phase of the PCR, because the Taq polymerase is not denatured by heating to 95 °C during the melting phase of each cyle. In 1989, the Taq polymerase gene was cloned and the Taq polymerase was produced in Escherichia coli as a recombinant protein. [73] [72] DNA of up to 35,000 basepairs was synthesized by Wayne M. Barnes by using different mixtures of A and B type polymerases, [36] [72] thereby creating the long-range PCR. The high synthesis rate of KOD polymerase was published in 1997 by Masahiro Takagi and colleagues, [3] [72] [14] thereby creating the fundamentals of high speed PCR. Other optimisations to the PCR were developed in the following years, e.g. circumventing PCR inhibitors and amplifying difficult GC-rich DNA sequences, [41] as well as modifying thermostable DNA polymerases by protein design. In 1998 the loop-mediated isothermal amplification was developed by Tsugunori Notomi and colleagues at Eiken Chemical Company, using Bst polymerase at 65 °C. [74] [75]

Further reading

Related Research Articles

<span class="mw-page-title-main">Polymerase chain reaction</span> Laboratory technique to multiply a DNA sample for study

The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation. Mullis and biochemist Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993.

Protein engineering is the process of developing useful or valuable proteins through the design and production of unnatural polypeptides, often by altering amino acid sequences found in nature. It is a young discipline, with much research taking place into the understanding of protein folding and recognition for protein design principles. It has been used to improve the function of many enzymes for industrial catalysis. It is also a product and services market, with an estimated value of $168 billion by 2017.

<span class="mw-page-title-main">DNA polymerase</span> Form of DNA replication

A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually work in groups to create two identical DNA duplexes from a single original DNA duplex. During this process, DNA polymerase "reads" the existing DNA strands to create two new strands that match the existing ones. These enzymes catalyze the chemical reaction

<span class="mw-page-title-main">DNA polymerase I</span> Family of enzymes

DNA polymerase I is an enzyme that participates in the process of prokaryotic DNA replication. Discovered by Arthur Kornberg in 1956, it was the first known DNA polymerase. It was initially characterized in E. coli and is ubiquitous in prokaryotes. In E. coli and many other bacteria, the gene that encodes Pol I is known as polA. The E. coli Pol I enzyme is composed of 928 amino acids, and is an example of a processive enzyme — it can sequentially catalyze multiple polymerisation steps without releasing the single-stranded template. The physiological function of Pol I is mainly to support repair of damaged DNA, but it also contributes to connecting Okazaki fragments by deleting RNA primers and replacing the ribonucleotides with DNA.

<i>Thermus aquaticus</i> Species of bacterium

Thermus aquaticus is a species of bacteria that can tolerate high temperatures, one of several thermophilic bacteria that belong to the Deinococcota phylum. It is the source of the heat-resistant enzyme Taq DNA polymerase, one of the most important enzymes in molecular biology because of its use in the polymerase chain reaction (PCR) DNA amplification technique.

Helicase-dependent amplification (HDA) is a method for in vitro DNA amplification that takes place at a constant temperature.

<span class="mw-page-title-main">Klenow fragment</span>

The Klenow fragment is a large protein fragment produced when DNA polymerase I from E. coli is enzymatically cleaved by the protease subtilisin. First reported in 1970, it retains the 5' → 3' polymerase activity and the 3’ → 5’ exonuclease activity for removal of precoding nucleotides and proofreading, but loses its 5' → 3' exonuclease activity.

<i>Taq</i> polymerase Thermostable form of DNA polymerase I used in polymerase chain reaction

Taq polymerase is a thermostable DNA polymerase I named after the thermophilic eubacterial microorganism Thermus aquaticus, from which it was originally isolated by Chien et al. in 1976. Its name is often abbreviated to Taq or Taq pol. It is frequently used in the polymerase chain reaction (PCR), a method for greatly amplifying the quantity of short segments of DNA.

Pfu DNA polymerase is an enzyme found in the hyperthermophilic archaeon Pyrococcus furiosus, where it functions to copy the organism's DNA during cell division. In the laboratory setting, Pfu is used to amplify DNA in the polymerase chain reaction (PCR), where the enzyme serves the central function of copying a new strand of DNA during each extension step.

<i>Pyrococcus furiosus</i> Species of archaeon

Pyrococcus furiosus is a heterotrophic, strictly anaerobic, extremophilic, model species of archaea. It is classified as a hyperthermophile because it thrives best under extremely high temperatures, and is notable for having an optimum growth temperature of 100 °C. P. furiosus belongs to the Pyrococcus genus, most commonly found in extreme environmental conditions of hydrothermal vents. It is one of the few prokaryotic organisms that has enzymes containing tungsten, an element rarely found in biological molecules.

<span class="mw-page-title-main">Thermostability</span> Ability of a substance to resist changes in structure under high temperatures

In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative temperature.

TaqMan probes are hydrolysis probes that are designed to increase the specificity of quantitative PCR. The method was first reported in 1991 by researcher Kary Mullis at Cetus Corporation, and the technology was subsequently developed by Hoffmann-La Roche for diagnostic assays and by Applied Biosystems for research applications.

The polymerase chain reaction (PCR) is a commonly used molecular biology tool for amplifying DNA, and various techniques for PCR optimization which have been developed by molecular biologists to improve PCR performance and minimize failure.

Loop-mediated isothermal amplification (LAMP) is a single-tube technique for the amplification of DNA for diagnostic purposes and a low-cost alternative to detect certain diseases. LAMP is an isothermal nucleic acid amplification technique. In contrast to the polymerase chain reaction (PCR) technology, in which the reaction is carried out with a series of alternating temperature steps or cycles, isothermal amplification is carried out at a constant temperature, and does not require a thermal cycler. LAMP was invented in 1998 by Eiken Chemical Company in Tokyo. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) combines LAMP with a reverse transcription step to allow the detection of RNA.

The versatility of polymerase chain reaction (PCR) has led to modifications of the basic protocol being used in a large number of variant techniques designed for various purposes. This article summarizes many of the most common variations currently or formerly used in molecular biology laboratories; familiarity with the fundamental premise by which PCR works and corresponding terms and concepts is necessary for understanding these variant techniques.

Topoisomerase-based cloning is a molecular biology technique in which DNA fragments are cloned into specific vectors without the requirement for DNA ligases. Taq polymerase has a nontemplate-dependent terminal transferase activity that adds a single deoxyadenosine (A) to the 3'-end of the PCR products. This characteristic is exploited in "sticky end" TOPO TA cloning. For "blunt end" TOPO cloning, the recipient vector does not have overhangs and blunt-ended DNA fragments can be cloned.

Multiple displacement amplification (MDA) is a DNA amplification technique. This method can rapidly amplify minute amounts of DNA samples to a reasonable quantity for genomic analysis. The reaction starts by annealing random hexamer primers to the template: DNA synthesis is carried out by a high fidelity enzyme, preferentially Φ29 DNA polymerase. Compared with conventional PCR amplification techniques, MDA does not employ sequence-specific primers but amplifies all DNA, generates larger-sized products with a lower error frequency, and works at a constant temperature. MDA has been actively used in whole genome amplification (WGA) and is a promising method for application to single cell genome sequencing and sequencing-based genetic studies.

Φ29 DNA polymerase is an enzyme from the bacteriophage Φ29. It is being increasingly used in molecular biology for multiple displacement DNA amplification procedures, and has a number of features that make it particularly suitable for this application. It was discovered and characterized by Spanish scientists Luis Blanco and Margarita Salas.

Recombinase polymerase amplification (RPA) is a single tube, isothermal alternative to the polymerase chain reaction (PCR). By adding a reverse transcriptase enzyme to an RPA reaction it can detect RNA as well as DNA, without the need for a separate step to produce cDNA,. Because it is isothermal, RPA can use much simpler equipment than PCR, which requires a thermal cycler. Operating best at temperatures of 37–42 °C and still working, albeit more slowly, at room temperature means RPA reactions can in theory be run quickly simply by holding a tube. This makes RPA an excellent candidate for developing low-cost, rapid, point-of-care molecular tests. An international quality assessment of molecular detection of Rift Valley fever virus performed as well as the best RT-PCR tests, detecting less concentrated samples missed by some PCR tests and an RT-LAMP test. RPA was developed and launched by TwistDx Ltd., a biotechnology company based in Cambridge, UK.

Pwo polymerase is a thermostable DNA polymerase used for the polymerase chain reaction. The abbreviation stands for Pyrococcus woesei, a thermophilic archaeon, from which this polymerase was isolated. This polymerase breaks when reaching erroneous uracil in DNA from the chain extension and, through this readahead function, fewer defective DNA clones are synthesized. It is used much less than the usual Taq or Pfu polymerases. This DNA polymerase, similar to other DNA polymerases from Archaebacteria is sensitive to Uracil residues in DNA and is strongly inhibited by dUTP or uracil residues in DNA. Other polymerases in this class are Pfu, Vent, Deep Vent and Pfx. The inhibition of this class of thermostable DNA polymerases limit their use in some applications of PCR, i.e. use of dUTP for prevention of carryover contamination as well as application involving dU containing primers such as ligase free cloning methods or site directed mutagenesis using UNG.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Promega: Properties of Thermostable DNA Polymerases (PDF; 208 kB). Accessed september 27, 2012.
  2. 1 2 3 4 5 6 7 8 9 10 I. Oscorbin, M. Filipenko: Bst polymerase - a humble relative of Taq polymerase. In: Computational and structural biotechnology journal. Volume 21, 2023, p. 4519–4535, doi : 10.1016/j.csbj.2023.09.008, PMID   37767105, PMC   1052051.
  3. 1 2 3 4 5 6 7 8 9 10 M. Takagi, M. Nishioka, H. Kakihara, M. Kitabayashi, H. Inoue, B. Kawakami, M. Oka, T. Imanaka: Characterization of DNA polymerase from Pyrococcus sp. strain KOD1 and its application to PCR. In: Appl. Environ. Microbiol., Volume 63, Issue 11, 1997, p. 4504–4510. PMID   9361436; PMC   168769.
  4. 1 2 3 4 5 6 7 8 J. Cline, J. C. Braman, H. H. Hogrefe: PCR fidelity of pfu DNA polymerase and other thermostable DNA polymerases. In: Nucleic Acids Res., Volume 24, Issue 18, 1996, p. 3546–3551. PMID   8836181; PMC   146123.
  5. 1 2 3 4 5 Potapov V, Ong JL (2017). "Examining Sources of Error in PCR by Single-Molecule Sequencing". PLOS ONE. 12 (1): e0169774. Bibcode:2017PLoSO..1269774P. doi: 10.1371/journal.pone.0169774 . PMC   5218489 . PMID   28060945.
  6. 1 2 3 4 P. McInerney, P. Adams, M. Z. Hadi: Error Rate Comparison during Polymerase Chain Reaction by DNA Polymerase. In: Molecular biology international. 2014, p. 287430, doi : 10.1155/2014/287430, PMID   25197572, PMC   4150459.
  7. Hong Guo Fan, Zhai Feng, Huang Wei-Hua: EP0810288 (A2) ― 1997-12-03: A new DNA polymerase with proof-reading 3'-5' exonuclease activity
  8. 1 2 3 4 5 6 Bahram Arezi, Weimei Xing, Joseph A. Sorge, Holly H. Hogrefe (2003-10-15), "Amplification efficiency of thermostable DNA polymerases" (PDF), Analytical Biochemistry , vol. 321, no. 2, pp. 226–235, doi:10.1016/S0003-2697(03)00465-2, PMID   14511688 {{citation}}: CS1 maint: multiple names: authors list (link)
  9. H.H. Hogrefe, M. Borns, High fidelity PCR enzymes, in: C.W. Dieffenbach, G.S. Dveksler (Eds.), PCR Primer: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 2003.
  10. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Agilent: High-Fidelity PCR Enzymes: Properties and Error Rate Determinations.
  11. 1 2 European Patent 1752534A1: Hochgeschwindigkeits-PCR unter Verwendung von Hochgeschwindigkeits-DNA-Polymerase, 2005-05-12 / 2007-02-14 by Toyo Boseki (applicant) & Masaya Segawa et al. (inventors).
  12. 1 2 3 4 T. A. Steitz: DNA polymerases: structural diversity and common mechanisms. In: Journal of Biological Chemistry. Volume 274, issue 25, June 1999, p. 17395–17398, doi : 10.1074/jbc.274.25.17395, PMID   10364165.
  13. P. J. Rothwell, G. Waksman: Structure and mechanism of DNA polymerases. In: Advances in protein chemistry. Volume 71, 2005, p. 401–440, doi : 10.1016/S0065-3233(04)71011-6, PMID   16230118.
  14. 1 2 H. Hashimoto, M. Nishioka, P. Fujiwara, M. Takagi, T. Imanaka, T. Inoue, Y. Kai: Crystal structure of DNA polymerase from hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1. In: Journal of molecular biology. Volume 306, issue 3, February 2001, p. 469–477, doi : 10.1006/jmbi.2000.4403, PMID   11178906.
  15. 1 2 B. Villbrandt, H. Sobek, B. Frey, D. Schomburg: Domain exchange: chimeras of Thermus aquaticus DNA polymerase, Escherichia coli DNA polymerase I and Thermotoga neapolitana DNA polymerase. In: Protein Eng., Vol. 13, Issue 9, 2000, p. 645–654. PMID   11054459.
  16. W. Abu Al-Soud, P. Râdström: Capacity of nine thermostable DNA polymerases to mediate DNA amplification in the presence of PCR-inhibiting samples. In: Appl. Environ. Microbiol., Vol. 64, Issue 10, 1998, p. 3748–3753. PMID   9758794; PMC   106538.
  17. A. Ghasemi, A. H. Salmanian, N. Sadeghifard, A. A. Salarian, M. K. Gholi: Cloning, expression and purification of Pwo polymerase from Pyrococcus woesei. In: Iranian journal of microbiology. Volume 3, issue 3, September 2011, p. 118–122, PMID   22347593, PMC   3279813.
  18. H. Kong, R. B. Kucera, W. E. Jack: Characterization of a DNA polymerase from the hyperthermophile archaea Thermococcus litoralis. Vent DNA polymerase, steady state kinetics, thermal stability, processivity, strand displacement, and exonuclease activities. In: J Biol Chem., Volume 268, Issue 3, 1993, p. 1965–1975. PMID   8420970.
  19. K. Böhlke, F. M. Pisani, C. E. Vorgias, B. Frey, H. Sobek, M. Rossi, G. Antranikian: PCR performance of the B-type DNA polymerase from the thermophilic euryarchaeon Thermococcus aggregans improved by mutations in the Y-GG/A motif. In: Nucleic Acids Res., Volume 28, Issue 20, 2000, p. 3910–3917. PMID   11024170; PMC   110800.
  20. K. P. Kim, H. Bae, I. H. Kim, p. T. Kwon: Cloning, expression, and PCR application of DNA polymerase from the hyperthermophilic archaeon, Thermococcus celer. In: Biotechnol Lett. (2011), Volume 33(2), p. 339–46. PMID   20953664.
  21. Y. Cho, H. p. Lee, Y. J. Kim, p. G. Kang, p. J. Kim, J. H. Lee: Characterization of a dUTPase from the hyperthermophilic archaeon Thermococcus onnurineus NA1 and its application in polymerase chain reaction amplification. In: Mar Biotechnol (NY), Volume 9, Issue 4, 2007, p. 450–458. PMID   17549447.
  22. 1 2 J. I. Lee, Y. J. Kim, H. Bae, p. p. Cho, J. H. Lee, p. T. Kwon: Biochemical properties and PCR performance of a family B DNA polymerase from hyperthermophilic euryarchaeon Thermococcus peptonophilus. In: Appl Biochem Biotechnol., Volume 160, Issue 6, 2010, p. 1585–1899. PMID   19440663.
  23. D. Marsic, J. M. Flaman, J. D. Ng: New DNA polymerase from the hyperthermophilic marine archaeon Thermococcus thioreducens. In: Extremophiles, Volume 12, Issue 6, 2008, p. 775–788. PMID   18670731.
  24. J. G. Song, E. J. Kil, p. p. Cho, I. H. Kim, p. T. Kwon: An amino acid residue in the middle of the fingers subdomain is involved in Neq DNA polymerase processivity: enhanced processivity of engineered Neq DNA polymerase and its PCR application. In: Protein Eng. Des. Sel., Volume 23, Issue 11, 2010, p. 835–842. PMID   20851826.
  25. J. Dietrich, P. Schmitt, M. Zieger, B. Preve, J. L. Rolland, H. Chaabihi, Y. Gueguen: PCR performance of the highly thermostable proof-reading B-type DNA polymerase from Pyrococcus abyssi. In: FEMS Microbiol Lett., Volume 217, Issue 1, 2002, p. 89–94. PMID   12445650.
  26. E. M. Kennedy, C. Hergott, p. Dewhurst, B. Kim: The mechanistic architecture of thermostable Pyrococcus furiosus family B DNA polymerase motif A and its interaction with the dNTP substrate. In: Biochemistry (2009), Volume 48(47), p. 11161–8. PMID   19817489; PMC   3097049.
  27. 1 2 T. Kuroita, H. Matsumura, N. Yokota, M. Kitabayashi, H. Hashimoto, T. Inoue, T. Imanaka, Y. Kai: Structural mechanism for coordination of proofreading and polymerase activities in archaeal DNA polymerases. In: J Mol Biol. (2005), Volume 351(2), p. 291–8. PMID   16019029. doi:10.1016/j.jmb.2005.06.015.
  28. J. P. McDonald, A. Hall, D. Gasparutto, J. Cadet, J. Ballantyne, R. Woodgate: Novel thermostable Y-family polymerases: applications for the PCR amplification of damaged or ancient DNAs. In: Nucleic Acids Res. (2006), Volume 34(4), p. 1102–11. PMID   16488882; PMC   1373694.
  29. E. Eremeeva, P. Herdewijn: PCR Amplification of Base-Modified DNA. In: Current protocols in chemical biology. Volume 10, issue 1, March 2018, p. 18–48, doi : 10.1002/cpch.33, PMID   30040232.
  30. X. Wang, J. Zhang, Y. Li, G. Chen, X. Wang: Enzymatic synthesis of modified oligonucleotides by PEAR using Phusion and KOD DNA polymerases. In: Nucleic acid therapeutics. Volume 25, issue 1, February 2015, p. 27–34, doi : 10.1089/nat.2014.0513, PMID   25517220, PMC   4296748.
  31. Y. Wang, D. E. Prosen, L. Mei, J. C. Sullivan, M. Finney, P. B. Vander Horn: A novel strategy to engineer DNA polymerases for enhanced processivity and improved performance in vitro. In: Nucleic Acids Res. (2004), Volume 32(3), p. 1197–207. PMID   14973201; PMC   373405.
  32. M. Motz, I. Kober, C. Girardot, E. Loeser, U. Bauer, M. Albers, G. Moeckel, E. Minch, H. Voss, C. Kilger, M. Koegl: Elucidation of an archaeal replication protein network to generate enhanced PCR enzymes. In: J Biol Chem. (2002), Volume 277(18), p. 16179–88. PMID   11805086. PDF.
  33. P. Forterre (2006), "DNA topoisomerase V: a new fold of mysterious origin", Trends Biotechnol , vol. 24, no. 6, pp. 245–247, doi:10.1016/j.tibtech.2006.04.006, PMID   16650908
  34. A. R. Pavlov, N. V. Pavlova, S. A. Kozyavkin, A. I. Slesarev: Recent developments in the optimization of thermostable DNA polymerases for efficient applications. In: Trends in Biotechnology. Volume 22, issue 5, May 2004, p. 253–260, doi : 10.1016/j.tibtech.2004.02.011, PMID   15109812.
  35. Holly H. Hogrefe, M. Borns: High fidelity PCR enzymes. In: C.W. Dieffenbach, G.p. Dveksler (Eds.): PCR Primer: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 2003.
  36. 1 2 3 W. M. Barnes: PCR amplification of up to 35-kb DNA with high fidelity and high yield from lambda bacteriophage templates. In: Proc Natl Acad Sci U S A (1994), Volume 91(6), p. 2216–20. PMID   8134376; PMC   43341.
  37. Bruno Frey, Bernhard Suppmann: Demonstration of the Expand TM PCR System's Greater Fidelity and Higher Yields with a lacI-based PCR Fidelity Assay. (2000).
  38. R. Tellier, J. Bukh, S. U. Emerson, R. H. Purcell: Long PCR amplification of large fragments of viral genomes: a technical overview. In: Methods in molecular biology. Volume 226, 2003, p. 167–172, doi : 10.1385/1-59259-384-4:167, PMID   12958497.
  39. M. Miura, C. Tanigawa, Y. Fujii, S. Kaneko: Comparison of six commercially-available DNA polymerases for direct PCR. In: Revista do Instituto de Medicina Tropical de Sao Paulo. Volume 55, issue 6, 2013, p. 401–406, doi : 10.1590/S0036-46652013000600005, PMID   24213192, PMC   4105087.
  40. H. H. Hogrefe, C. J. Hansen, B. R. Scott, K. B. Nielson: Archaeal dUTPase enhances PCR amplifications with archaeal DNA polymerases by preventing dUTP incorporation. In: Proceedings of the National Academy of Sciences. Volume 99, issue 2, January 2002, p. 596–601, doi : 10.1073/pnas.012372799, PMID   11782527, PMC   117351.
  41. 1 2 H. Karunanathie, P. S. Kee, S. F. Ng, M. A. Kennedy, E. W. Chua: PCR enhancers: Types, mechanisms, and applications in long-range PCR. In: Biochimie. Volume 197, June 2022, p. 130–143, doi : 10.1016/j.biochi.2022.02.009, PMID   35231536.
  42. US Patent 2013034879A1: DNA Polymerases, 2012-08-02 / 2007-02-14, Fermentas UAB et Al (applicant), Remigijus Skirgaila et al. (inventors).
  43. US Patent 2009280539A1: DNA Polymerases and related methods, 2009-04-16 / 2009-11-12, Roche Molecular Systems Inc (applicant), Keith A. Bauer (inventor).
  44. J. Li, Y. Li, Y. Li, Y. Ma, W. Xu, J. Wang: An enhanced activity and thermostability of chimeric Bst DNA polymerase for isothermal amplification applications. In: Applied Microbiology and Biotechnology. Volume 107, issue 21, November 2023, S. 6527–6540, doi : 10.1007/s00253-023-12751-6, PMID   37672070.
  45. W. M. Barnes: The fidelity of Taq polymerase catalyzing PCR is improved by an N-terminal deletion. In: Gene (1992), Volume 112(1), p. 29–35. PMID   1551596.
  46. L. p. Merkens, p. K. Bryan, R. E. Moses: Inactivation of the 5'-3' exonuclease of Thermus aquaticus DNA polymerase. In: Biochim Biophys Acta (1995), Volume 1264(2), p. 243–8. PMID   7495870.
  47. p. Tabor, C. C. Richardson: A single residue in DNA polymerases of the Escherichia coli DNA polymerase I family is critical for distinguishing between deoxy- and dideoxyribonucleotides. In: Proc Natl Acad Sci U S A., Volume 92, Issue 14, 1995, p. 6339–6343. PMID   7603992; PMC   41513.
  48. P. B. Vander Horn, M. C. Davis, J. J. Cunniff, C. Ruan, B. F. McArdle, p. B. Samols, J. Szasz, G. Hu, K. M. Hujer, p. T. Domke, p. R. Brummet, R. B. Moffett, C. W. Fuller: Thermo sequenase DNA polymerase and T. acidophilum pyrophosphatase: new thermostable enzymes for DNA sequencing. In: Biotechniques, Volume 22, Issue 4, 1997, p. 758–762, 764–765. PMID   9105629.
  49. J. M. Prober, G. L. Trainor, R. J. Dam, F. W. Hobbs, C. W. Robertson, R. J. Zagursky, A. J. Cocuzza, M. A. Jensen, K. Baumeister: A system for rapid DNA sequencing with fluorescent chain-terminating dideoxynucleotides. In: Science, Volume 238, Issue 4825, 1987, p. 336–341. PMID   2443975.
  50. R. T. D'Aquila, L. J. Bechtel, J. A. Videler, J. J. Eron, P. Gorczyca, J. C. Kaplan: Maximizing sensitivity and specificity of PCR by pre-amplification heating. In: Nucleic acids research. Volume 19, issue 13, July 1991, p. 3749, doi : 10.1093/nar/19.13.3749, PMID   1852616, PMC   328414.
  51. S. Buratowski: Hot Start Taq purification. 2015.
  52. T. G. Graham, C. Dugast-Darzacq, G. M. Dailey, X. H. Nguyenla, E. Van Dis, M. N. Esbin, A. Abidi, S. A. Stanley, X. Darzacq, R. Tjian: Open-source RNA extraction and RT-qPCR methods for SARS-CoV-2 detection. In: PLOS ONE. Volume 16, issue 2, 2021, p. e0246647, doi : 10.1371/journal.pone.0246647, PMID   33534838, PMC   7857565.
  53. David Edward Birch, Walter Joseph Laird, Michael Anthony Zoccoli: Nucleic acid amplification using a reversibly inactivated thermostable enzyme. United States Patent 5773258.
  54. 1 2 W. M. Barnes, K. R. Rowlyk: Magnesium precipitate hot start method for PCR. In: Molecular and cellular probes. Volume 16, issue 3, June 2002, p. 167–171, doi : 10.1006/mcpr.2002.0407, PMID   12219733.
  55. N. Paul, J. Shum, T. Le: Hot start PCR. In: Methods Mol Biol. (2010), Volume 630, p. 301–18. PMID   20301005.
  56. M. F. Kramer, D. M. Coen: Enzymatic amplification of DNA by PCR: standard procedures and optimization. In: Curr Protoc Immunol. (2001), Chapter 10, Unit 10.20. PMID   18432685.
  57. H. FRAENKEL-CONRAT, B. A. BRANDON, H. S. OLCOTT: The reaction of formaldehyde with proteins; participation of indole groups; gramicidin. In: The Journal of biological chemistry. Volume 168, issue 1, April 1947, ISSN   0021-9258, p. 99–118, PMID   20291066.
  58. H. FRAENKEL-CONRAT, H. S. OLCOTT: The reaction of formaldehyde with proteins; cross-linking between amino and primary amide or guanidyl groups. In: Journal of the American Chemical Society. Volume 70, issue 8, August 1948, ISSN   0002-7863, p. 2673–2684, PMID   18876976.
  59. H. FRAENKEL-CONRAT, H. S. OLCOTT: Reaction of formaldehyde with proteins; cross-linking of amino groups with phenol, imidazole, or indole groups. In: The Journal of biological chemistry. Volume 174, issue 3, July 1948, ISSN   0021-9258, p. 827–843, PMID   18871242.
  60. D. E. Kellogg, I. Rybalkin, S. Chen, N. Mukhamedova, T. Vlasik, P. D. Siebert, A. Chenchik: TaqStart Antibody: "hot start" PCR facilitated by a neutralizing monoclonal antibody directed against Taq DNA polymerase. In: BioTechniques. Volume 16, issue 6, June 1994, p. 1134–1137, PMID   8074881.
  61. D. J. Sharkey, E. R. Scalice, K. G. Christy, S. M. Atwood, J. L. Daiss: Antibodies as thermolabile switches: high temperature triggering for the polymerase chain reaction. In: Bio/technology. Volume 12, issue 5, May 1994, p. 506–509, doi : 10.1038/nbt0594-506, PMID   7764710.
  62. O. Y. Yakimovich, Y. I. Alekseev, A. V. Maksimenko, O. L. Voronina, V. G. Lunin: Influence of DNA aptamer structure on the specificity of binding to Taq DNA polymerase. In: Biochemistry. Biokhimiia. Volume 68, issue 2, February 2003, p. 228–235, doi : 10.1023/a:1022609714768, PMID   12693970.
  63. T. Noma, K. Sode, K. Ikebukuro: Characterization and application of aptamers for Taq DNA polymerase selected using an evolution-mimicking algorithm. In: Biotechnology letters. Volume 28, issue 23, December 2006, p. 1939–1944, doi : 10.1007/s10529-006-9178-4, PMID   16988782.
  64. Q. Chou, M. Russell, D. E. Birch, J. Raymond, W. Bloch: Prevention of pre-PCR mis-priming and primer dimerization improves low-copy-number amplifications. In: Nucleic Acids Res. (1992), volume 20, issue 7, p. 1717–23. PMID   1579465; PMC   312262.
  65. Carlos D. Ordóñez, Modesto Redrejo‐Rodríguez: DNA Polymerases for Whole Genome Amplification: Considerations and Future Directions. In: International Journal of Molecular Sciences. 2023, volume 24, issue 11, p. 9331 doi : 10.3390/ijms24119331. PMID   37298280. PMC   10253169.
  66. B. Fuchs, K. Zhang, M. G. Rock, M. E. Bolander, G. Sarkar: High temperature cDNA synthesis by AMV reverse transcriptase improves the specificity of PCR. In: Molecular biotechnology. Volume 12, issue 3, October 1999, p. 237–240, doi : 10.1385/MB:12:3:237, PMID   10631680.
  67. A. M. Carothers, G. Urlaub, J. Mucha, D. Grunberger, L. A. Chasin: Point mutation analysis in a mammalian gene: rapid preparation of total RNA, PCR amplification of cDNA, and Taq sequencing by a novel method. In: BioTechniques. Volume 7, issue 5, May 1989, p. 494–6, 498, PMID   2483818.
  68. T. W. Myers, D. H. Gelfand: Reverse transcription and DNA amplification by a Thermus thermophilus DNA polymerase. In: Biochemistry (1991), Band 30(31), S. 7661–6. PMID   1714296.
  69. M. J. Moser, R. A. DiFrancesco, K. Gowda, A. J. Klingele, D. R. Sugar, S. Stocki, D. A. Mead, T. W. Schoenfeld: Thermostable DNA polymerase from a viral metagenome is a potent RT-PCR enzyme. In: PLoS One (2012), volume 7(6), p. e38371. doi : 10.1371/journal.pone.0038371. PMID   22675552; PMC   3366922.
  70. Chien A, Edgar DB, Trela JM (September 1976). "Deoxyribonucleic acid polymerase from the extreme thermophile Thermus aquaticus". Journal of Bacteriology. 127 (3): 1550–1557. doi:10.1128/JB.127.3.1550-1557.1976. PMC   232952 . PMID   8432.
  71. R. K. Saiki, D. H. Gelfand, P. Stoffel, P. J. Scharf, R. Higuchi, G. T. Horn, K. B. Mullis, H. A. Erlich: Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. In: Science. Volume 239, issue 4839, January 1988, p. 487–491, doi : 10.1126/science.2448875, PMID   2448875.
  72. 1 2 3 4 P. Ishino, Y. Ishino: DNA polymerases as useful reagents for biotechnology - the history of developmental research in the field. In: Frontiers in Microbiology. Volume 5, 2014, p. 465, doi : 10.3389/fmicb.2014.00465, PMID   25221550, PMC   4148896.
  73. F. C. Lawyer, P. Stoffel, R. K. Saiki, K. Myambo, R. Drummond, D. H. Gelfand: Isolation, characterization, and expression in Escherichia coli of the DNA polymerase gene from Thermus aquaticus. In: Journal of Biological Chemistry. Volume 264, issue 11, April 1989, p. 6427–6437, PMID   2649500.
  74. M. Soroka, B. Wasowicz, A. Rymaszewska: Loop-Mediated Isothermal Amplification (LAMP): The Better Sibling of PCR? In: Cells. Volume 10, issue 8, July 2021, p. , doi : 10.3390/cells10081931, PMID   34440699, PMC   8393631.
  75. Notomi T, Okayama H, Masubuchi H, Yonekawa T, Watanabe K, Amino N, Hase T (2000). "Loop-mediated isothermal amplification of DNA". Nucleic Acids Res. 28 (12): 63e–63. doi:10.1093/nar/28.12.e63. PMC   102748 . PMID   10871386.