1
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Huber LB, Betz K, Marx A. Reverse Transcriptases: From Discovery and Applications to Xenobiology. Chembiochem 2023; 24:e202200521. [PMID: 36354312 DOI: 10.1002/cbic.202200521] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/09/2022] [Indexed: 11/12/2022]
Abstract
Reverse transcriptases are DNA polymerases that can use RNA as a template for DNA synthesis. They thus catalyze the reverse of transcription. Although discovered in 1970, reverse transcriptases are still of great interest and are constantly being further developed for numerous modern research approaches. They are frequently used in biotechnological and molecular diagnostic applications. In this review, we describe the discovery of these fascinating enzymes and summarize research results and applications ranging from molecular cloning, direct virus detection, and modern sequencing methods to xenobiology.
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Affiliation(s)
- Luisa B Huber
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78464, Konstanz, Germany
| | - Karin Betz
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78464, Konstanz, Germany
| | - Andreas Marx
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, 78464, Konstanz, Germany
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2
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Oscorbin IP, Wong PF, Boyarskikh UA, Khrapov EA, Filipenko ML. The attachment of a DNA-binding Sso7d-like protein improves processivity and resistance to inhibitors of M-MuLV reverse transcriptase. FEBS Lett 2020; 594:4338-4356. [PMID: 32970841 DOI: 10.1002/1873-3468.13934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/23/2020] [Accepted: 09/08/2020] [Indexed: 11/09/2022]
Abstract
Reverse transcriptases (RTs) are a standard tool in both fundamental studies and diagnostics. RTs should possess elevated temperature optimum, high thermal stability, processivity and tolerance to contaminants. Here, we constructed a set of chimeric RTs, based on the combination of the Moloney murine leukaemia virus (M-MuLV) RT and either of two DNA-binding domains: the DNA-binding domain of the DNA ligase from Pyrococcus abyssi or the DNA-binding Sto7d protein from Sulfolobus tokodaii. The processivity and efficiency of cDNA synthesis of the chimeric RT with Sto7d at the C-end are increased several fold. The attachment of Sto7d enhances the tolerance of M-MuLV RT to the most common amplification inhibitors: NaCl, urea, guanidinium chloride, formamide, components of human whole blood and human blood plasma. Thus, fusing M-MuLV RT with an additional domain results in more robust and efficient RTs.
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Affiliation(s)
- Igor P Oscorbin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - Pei Fong Wong
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - Ulyana A Boyarskikh
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - Evgeny A Khrapov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Maksim L Filipenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
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3
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Yasukawa K, Yanagihara I, Fujiwara S. Alteration of enzymes and their application to nucleic acid amplification (Review). Int J Mol Med 2020; 46:1633-1643. [PMID: 33000189 PMCID: PMC7521554 DOI: 10.3892/ijmm.2020.4726] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 05/29/2020] [Indexed: 12/17/2022] Open
Abstract
Since the discovery of polymerase chain reaction (PCR) in 1985, several methods have been developed to achieve nucleic acid amplification, and are currently used in various fields including clinical diagnosis and life science research. Thus, a wealth of information has accumulated regarding nucleic acid-related enzymes. In this review, some nucleic acid-related enzymes were selected and the recent advances in their modification along with their application to nucleic acid amplification were described. The discussion also focused on optimization of the corresponding reaction conditions. Using newly developed enzymes under well-optimized reaction conditions, the sensitivity, specificity, and fidelity of nucleic acid tests can be improved successfully.
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Affiliation(s)
- Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606‑8502, Japan
| | - Itaru Yanagihara
- Department of Developmental Medicine, Research Institute, Osaka Women's and Children's Hospital, Izumi, Osaka 594‑1101, Japan
| | - Shinsuke Fujiwara
- Department of Bioscience, School of Science and Technology, Kwansei‑Gakuin University, Sanda, Hyogo 669‑1337, Japan
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4
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Little RC, Whitfield CJ, Tuite EM, Pike AR. The Synthesis of Designer DNA. Methods Mol Biol 2018; 1811:11-21. [PMID: 29926443 DOI: 10.1007/978-1-4939-8582-1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The synthesis of designer DNA requires an approach where the user can determine both the sequence and the number of nucleobases. The protocol outlined here describes an enzymatic method for the synthesis of long repeat-sequence DNA. The method utilizes a PCR-based approach; starting with short oligo-seeds, c.a. 20 bp, bearing a minimum of two repeating units of >8 bp sequences. During each heat-cool cycle, the oligo-seeds reanneal imperfectly leaving an overhang, which is then extended by the polymerase. The final length of the DNA is determined by the number of heat-cool cycles performed, reaching up to 20,000 bp after 20 cycles.
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Affiliation(s)
- Rachel C Little
- School of Chemistry, Newcastle University, Newcastle Upon Tyne, UK
| | | | - Eimer M Tuite
- School of Chemistry, Newcastle University, Newcastle Upon Tyne, UK
| | - Andrew R Pike
- School of Chemistry, Newcastle University, Newcastle Upon Tyne, UK.
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5
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Penno C, Kumari R, Baranov PV, van Sinderen D, Atkins JF. Stimulation of reverse transcriptase generated cDNAs with specific indels by template RNA structure: retrotransposon, dNTP balance, RT-reagent usage. Nucleic Acids Res 2017; 45:10143-10155. [PMID: 28973469 PMCID: PMC5737552 DOI: 10.1093/nar/gkx689] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/24/2017] [Indexed: 01/03/2023] Open
Abstract
RNA dependent DNA-polymerases, reverse transcriptases, are key enzymes for retroviruses and retroelements. Their fidelity, including indel generation, is significant for their use as reagents including for deep sequencing. Here, we report that certain RNA template structures and G-rich sequences, ahead of diverse reverse transcriptases can be strong stimulators for slippage at slippage-prone template motif sequence 3′ of such ‘slippage-stimulatory’ structures. Where slippage is stimulated, the resulting products have one or more additional base(s) compared to the corresponding template motif. Such structures also inhibit slippage-mediated base omission which can be more frequent in the absence of a relevant stem–loop. Slippage directionality, base insertion and omission, is sensitive to the relative concentration ratio of dNTPs specified by the RNA template slippage-prone sequence and its 5′ adjacent base. The retrotransposon-derived enzyme TGIRT exhibits more slippage in vitro than the retroviral enzymes tested including that from HIV. Structure-mediated slippage may be exhibited by other polymerases and enrich gene expression. A cassette from Drosophila retrotransposon Dme1_chrX_2630566, a candidate for utilizing slippage for its GagPol synthesis, exhibits strong slippage in vitro. Given the widespread occurrence and importance of retrotransposons, systematic studies to reveal the extent of their functional utilization of RT slippage are merited.
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Affiliation(s)
- Christophe Penno
- School of Biochemistry, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Romika Kumari
- School of Biochemistry, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- School of Microbiology, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - John F Atkins
- School of Biochemistry, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland.,Department of Human Genetics, University of Utah, Salt Lake City, UT 84112-5330, USA
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6
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Kumar S, Arumugam N, Permaul K, Singh S. Chapter 5 Thermostable Enzymes and Their Industrial Applications. Microb Biotechnol 2016. [DOI: 10.1201/9781315367880-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
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7
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Ellefson JW, Gollihar J, Shroff R, Shivram H, Iyer VR, Ellington AD. Synthetic evolutionary origin of a proofreading reverse transcriptase. Science 2016; 352:1590-3. [PMID: 27339990 DOI: 10.1126/science.aaf5409] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/31/2016] [Indexed: 12/18/2022]
Abstract
Most reverse transcriptase (RT) enzymes belong to a single protein family of ancient evolutionary origin. These polymerases are inherently error prone, owing to their lack of a proofreading (3'- 5' exonuclease) domain. To determine if the lack of proofreading is a historical coincidence or a functional limitation of reverse transcription, we attempted to evolve a high-fidelity, thermostable DNA polymerase to use RNA templates efficiently. The evolutionarily distinct reverse transcription xenopolymerase (RTX) actively proofreads on DNA and RNA templates, which greatly improves RT fidelity. In addition, RTX enables applications such as single-enzyme reverse transcription-polymerase chain reaction and direct RNA sequencing without complementary DNA isolation. The creation of RTX confirms that proofreading is compatible with reverse transcription.
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Affiliation(s)
- Jared W Ellefson
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA.
| | - Jimmy Gollihar
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA
| | - Raghav Shroff
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA
| | - Haridha Shivram
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA
| | - Vishwanath R Iyer
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA
| | - Andrew D Ellington
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas, 2500 Speedway, Austin, TX 78712, USA.
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8
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Guilliam TA, Keen BA, Brissett NC, Doherty AJ. Primase-polymerases are a functionally diverse superfamily of replication and repair enzymes. Nucleic Acids Res 2015; 43:6651-64. [PMID: 26109351 PMCID: PMC4538821 DOI: 10.1093/nar/gkv625] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/04/2015] [Indexed: 11/18/2022] Open
Abstract
Until relatively recently, DNA primases were viewed simply as a class of proteins that synthesize short RNA primers requisite for the initiation of DNA replication. However, recent studies have shown that this perception of the limited activities associated with these diverse enzymes can no longer be justified. Numerous examples can now be cited demonstrating how the term ‘DNA primase’ only describes a very narrow subset of these nucleotidyltransferases, with the vast majority fulfilling multifunctional roles from DNA replication to damage tolerance and repair. This article focuses on the archaeo-eukaryotic primase (AEP) superfamily, drawing on recently characterized examples from all domains of life to highlight the functionally diverse pathways in which these enzymes are employed. The broad origins, functionalities and enzymatic capabilities of AEPs emphasizes their previous functional misannotation and supports the necessity for a reclassification of these enzymes under a category called primase-polymerases within the wider functional grouping of polymerases. Importantly, the repositioning of AEPs in this way better recognizes their broader roles in DNA metabolism and encourages the discovery of additional functions for these enzymes, aside from those highlighted here.
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Affiliation(s)
- Thomas A Guilliam
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Benjamin A Keen
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Nigel C Brissett
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
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9
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Whitfield CJ, Turley AT, Tuite EM, Connolly BA, Pike AR. Enzymatic Method for the Synthesis of Long DNA Sequences with Multiple Repeat Units. Angew Chem Int Ed Engl 2015; 54:8971-4. [DOI: 10.1002/anie.201502971] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Indexed: 11/09/2022]
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10
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Whitfield CJ, Turley AT, Tuite EM, Connolly BA, Pike AR. Enzymatic Method for the Synthesis of Long DNA Sequences with Multiple Repeat Units. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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11
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Jozwiakowski SK, Keith BJ, Gilroy L, Doherty AJ, Connolly BA. An archaeal family-B DNA polymerase variant able to replicate past DNA damage: occurrence of replicative and translesion synthesis polymerases within the B family. Nucleic Acids Res 2014; 42:9949-63. [PMID: 25063297 PMCID: PMC4150786 DOI: 10.1093/nar/gku683] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A mutant of the high fidelity family-B DNA polymerase from the archaeon Thermococcus gorgonarius (Tgo-Pol), able to replicate past DNA lesions, is described. Gain of function requires replacement of the three amino acid loop region in the fingers domain of Tgo-Pol with a longer version, found naturally in eukaryotic Pol ζ (a family-B translesion synthesis polymerase). Inactivation of the 3′–5′ proof-reading exonuclease activity is also necessary. The resulting Tgo-Pol Z1 variant is proficient at initiating replication from base mismatches and can read through damaged bases, such as abasic sites and thymine photo-dimers. Tgo-Pol Z1 is also proficient at extending from primers that terminate opposite aberrant bases. The fidelity of Tgo-Pol Z1 is reduced, with a marked tendency to make changes at G:C base pairs. Together, these results suggest that the loop region of the fingers domain may play a critical role in determining whether a family-B enzyme falls into the accurate genome-replicating category or is an error-prone translesion synthesis polymerase. Tgo-Pol Z1 may also be useful for amplification of damaged DNA.
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Affiliation(s)
- Stanislaw K Jozwiakowski
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK Institute of Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Brian J Keith
- Institute of Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Louise Gilroy
- Institute of Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK
| | - Bernard A Connolly
- Institute of Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
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PPL2 translesion polymerase is essential for the completion of chromosomal DNA replication in the African trypanosome. Mol Cell 2014; 52:554-65. [PMID: 24267450 PMCID: PMC3898837 DOI: 10.1016/j.molcel.2013.10.034] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/07/2013] [Accepted: 10/15/2013] [Indexed: 01/23/2023]
Abstract
Faithful copying of the genome is essential for life. In eukaryotes, a single archaeo-eukaryotic primase (AEP), DNA primase, is required for the initiation and progression of DNA replication. Here we have identified additional eukaryotic AEP-like proteins with DNA-dependent primase and/or polymerase activity. Uniquely, the genomes of trypanosomatids, a group of kinetoplastid protozoa of significant medical importance, encode two PrimPol-like (PPL) proteins. In the African trypanosome, PPL2 is a nuclear enzyme present in G2 phase cells. Following PPL2 knockdown, a cell-cycle arrest occurs after the bulk of DNA synthesis, the DNA damage response is activated, and cells fail to recover. Consistent with this phenotype, PPL2 replicates damaged DNA templates in vitro, including templates containing the UV-induced pyrimidine-pyrimidone (6-4) photoproduct. Furthermore, PPL2 accumulates at sites of nuclear DNA damage. Taken together, our results indicate an essential role for PPL2 in postreplication tolerance of endogenous DNA damage, thus allowing completion of genome duplication. Trypanosomatids contain two archaeo-eukaryotic primase-polymerase-like proteins PPL2 is essential in the pathogenic bloodstream form African trypanosome PPL2 suppresses DNA damage and allows completion of chromosomal replication PPL2 mediates translesion DNA synthesis
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Gill S, Krupovic M, Desnoues N, Béguin P, Sezonov G, Forterre P. A highly divergent archaeo-eukaryotic primase from the Thermococcus nautilus plasmid, pTN2. Nucleic Acids Res 2014; 42:3707-19. [PMID: 24445805 PMCID: PMC3973330 DOI: 10.1093/nar/gkt1385] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We report the characterization of a DNA primase/polymerase protein (PolpTN2) encoded by the pTN2 plasmid from Thermococcus nautilus. Sequence analysis revealed that this protein corresponds to a fusion between an N-terminal domain homologous to the small catalytic subunit PriS of heterodimeric archaeal and eukaryotic primases (AEP) and a C-terminal domain related to their large regulatory subunit PriL. This unique domain configuration is not found in other virus- and plasmid-encoded primases in which PriS-like domains are typically fused to different types of helicases. PolpTN2 exhibited primase, polymerase and nucleotidyl transferase activities and specifically incorporates dNTPs, to the exclusion of rNTPs. PolpTN2 could efficiently prime DNA synthesis by the T. nautilus PolB DNA polymerase, suggesting that it is used in vivo as a primase for pTN2 plasmid replication. The N-terminal PriS-like domain of PolpTN2 exhibited all activities of the full-length enzyme but was much less efficient in priming cellular DNA polymerases. Surprisingly, the N-terminal domain possesses reverse transcriptase activity. We speculate that this activity could reflect an ancestral function of AEP proteins in the transition from the RNA to the DNA world.
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Affiliation(s)
- Sukhvinder Gill
- Institut Pasteur Unité Biologie Moléculaire du Gène chez les Extrêmophiles, 25 rue du Docteur Roux, 75015 Paris, France, CNRS UMR 7138 Systématique, Adaptation, Evolution, Université Paris 6 quai Saint-Bernard, 75252 Paris Cedex 05, France and Univ Paris-Sud Institut de Génétique et Microbiologie, CNRS UMR 8621, Orsay 91406, France
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Abstract
Ribonucleases H or RNases H are conserved and exist in almost every organism. They generate and remove RNA primers, which are required for DNA replication. RNases H hydrolyze RNA in RNA-DNA hybrids. RNases H and related enzymes contribute to reduction of gene expression in antisense and small-interfering RNA mechanisms for gene silencing. Retroviruses code for RNases H, which are required for DNA provirus synthesis. Their RNase H is fused to the reverse transcriptase and essential for virus replication inside the cell. Retroviruses code for four enzymes, three of which have been targeted by antiretroviral therapies. A drug against the fourth one, the retroviral RNase H, does not yet exist. The viral but not cellular RNases H should be targeted by drug design. Some details will be discussed here. Furthermore, a compound is described, which enables the RNase H to kill cell-free HIV particles by driving the virus into suicide - with potential use as a microbicide.
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15
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Pinheiro VB, Holliger P. The XNA world: progress towards replication and evolution of synthetic genetic polymers. Curr Opin Chem Biol 2012; 16:245-52. [PMID: 22704981 DOI: 10.1016/j.cbpa.2012.05.198] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 05/16/2012] [Accepted: 05/21/2012] [Indexed: 01/25/2023]
Abstract
Life's diversity is built on the wide range of properties and functions that can be encoded in natural biopolymers such as polypeptides and nucleic acids. However, despite their versatility, the range of chemical functionalities is limited, particularly in the case of nucleic acids. Chemical modification of nucleic acids can greatly increase their functional diversity but access to the full phenotypic potential of such polymers requires a system of replication. Here we review progress in the chemical and enzymatic synthesis, replication and evolution of unnatural nucleic acid polymers, which promises to enable the exploration of a vast sequence space not accessible to nature and deliver ligands, catalysts and materials based on this new class of biopolymers.
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Affiliation(s)
- Vitor B Pinheiro
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
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Sano S, Yamada Y, Shinkawa T, Kato S, Okada T, Higashibata H, Fujiwara S. Mutations to create thermostable reverse transcriptase with bacterial family A DNA polymerase from Thermotoga petrophila K4. J Biosci Bioeng 2011; 113:315-21. [PMID: 22143068 DOI: 10.1016/j.jbiosc.2011.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 10/31/2011] [Accepted: 11/01/2011] [Indexed: 11/28/2022]
Abstract
Family A DNA polymerase (K4PolI) from Thermotoga petrophila K4 was obtained as a recombinant form, and the enzyme characteristics were analyzed. K4PolI showed thermostable DNA-dependent DNA polymerase activity with 3'-5' exonuclease activity but no detectable RNA-dependent DNA polymerase activity. Its tertiary structure was speculated by in silico modeling to understand the binding situation between K4PolI and template DNA. Nine amino acids in the 3'-5' exonuclease domain are predicted to be involved in DNA/RNA distinction by steric interference with the 2' hydroxy group of ribose. To allow K4PolI to accept RNA as the template, mutants were constructed focusing on the amino acids located around the 2' hydroxyl group of the bound ribose. The mutants in which Thr326, Leu329, Gln384, Phe388, Met408, or Tyr438 was replaced with Ala (designated as T326A, L329A, Q384A, F388A, M408A, or Y438A, respectively) showed RNA-dependent DNA polymerase activity. All the mutants showed reduced 3'-5' exonuclease activity, suggesting that gain of reverse transcriptase activity is correlated with loss of 3'-5' exonuclease activity. In particular, the mutants enabled direct DNA amplification in a single tube format from structured RNA that was not efficiently amplified by retroviral reverse transcriptase.
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Affiliation(s)
- Sotaro Sano
- Department of Bioscience, Graduate School of Science and Technology, Kwansei-Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
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