1
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Laatri S, El Khayari S, Qriouet Z. Exploring the molecular aspect and updating evolutionary approaches to the DNA polymerase enzymes for biotechnological needs: A comprehensive review. Int J Biol Macromol 2024; 276:133924. [PMID: 39033894 DOI: 10.1016/j.ijbiomac.2024.133924] [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] [Received: 03/10/2024] [Revised: 07/07/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024]
Abstract
DNA polymerases are essential enzymes that play a key role in living organisms, as they participate in the synthesis and maintenance of the DNA molecule. The intrinsic properties of these enzymes have been widely observed and studied to understand their functions, activities, and behavior, which has allowed their natural power in DNA synthesis to be exploited in modern biotechnology, to the point of making them true pillars of the field. In this context, the laboratory evolution of these enzymes, either by directed evolution or rational design, has led to the generation of a wide range of new DNA polymerases with novel properties, suitable for a variety of biotechnological needs. In this review, we examine DNA polymerases at the molecular level, their biotechnological use, and their evolutionary methods in relation to the novel properties sought, providing a chronological selection of evolved DNA polymerases cited in the literature that we consider to be of great interest. To our knowledge, this work is the first to bring together the molecular, functional and evolutionary aspects of the DNA polymerase enzyme. We believe it will be of great interest to researchers whose aim is to produce new lines of evolved DNA polymerases.
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Affiliation(s)
- Said Laatri
- Microbiology and Molecular Biology Laboratory, Faculty of Sciences, Mohammed V-Souissi University, Rabat 10100, Morocco.
| | | | - Zidane Qriouet
- Pharmacology and Toxicology Laboratory, Faculty of Medicine and Pharmacy, Mohammed V-Souissi University, Rabat 10100, Morocco
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2
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Gustavsson E, Grünewald K, Elias P, Hällberg BM. Dynamics of the Herpes simplex virus DNA polymerase holoenzyme during DNA synthesis and proof-reading revealed by Cryo-EM. Nucleic Acids Res 2024; 52:7292-7304. [PMID: 38806233 PMCID: PMC11229320 DOI: 10.1093/nar/gkae374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 04/16/2024] [Accepted: 04/25/2024] [Indexed: 05/30/2024] Open
Abstract
Herpes simplex virus 1 (HSV-1), a double-stranded DNA virus, replicates using seven essential proteins encoded by its genome. Among these, the UL30 DNA polymerase, complexed with the UL42 processivity factor, orchestrates leading and lagging strand replication of the 152 kb viral genome. UL30 polymerase is a prime target for antiviral therapy, and resistance to current drugs can arise in immunocompromised individuals. Using electron cryo-microscopy (cryo-EM), we unveil the dynamic changes of the UL30/UL42 complex with DNA in three distinct states. First, a pre-translocation state with an open fingers domain ready for nucleotide incorporation. Second, a halted elongation state where the fingers close, trapping dATP in the dNTP pocket. Third, a DNA-editing state involving significant conformational changes to allow DNA realignment for exonuclease activity. Additionally, the flexible UL30 C-terminal domain interacts with UL42, forming an extended positively charged surface binding to DNA, thereby enhancing processive synthesis. These findings highlight substantial structural shifts in the polymerase and its DNA interactions during replication, offering insights for future antiviral drug development.
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Affiliation(s)
- Emil Gustavsson
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Building 15, 22607 Hamburg, Germany
| | - Kay Grünewald
- Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Building 15, 22607 Hamburg, Germany
- Leibniz-Institute of Virology, Martinistraße 52, 20251 Hamburg, Germany
- Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Per Elias
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden
| | - B Martin Hällberg
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Building 15, 22607 Hamburg, Germany
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3
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Lawler JL, Terrell S, Coen DM. The conserved RNP motif of the herpes simplex virus 1 family B DNA polymerase is crucial for viral DNA synthesis but not polymerase activity. Virology 2024; 594:110035. [PMID: 38554655 DOI: 10.1016/j.virol.2024.110035] [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] [Received: 01/08/2024] [Revised: 02/08/2024] [Accepted: 02/21/2024] [Indexed: 04/02/2024]
Abstract
The herpes simplex virus 1 DNA polymerase contains a highly conserved structural motif found in most family B polymerases and certain RNA-binding proteins. To investigate its importance within cells, we constructed a mutant virus with substitutions in two residues of the motif and a rescued derivative. The substitutions resulted in severe impairment of plaque formation, yields of infectious virus, and viral DNA synthesis while not meaningfully affecting expression of the mutant enzyme, its co-localization with the viral single-stranded DNA binding protein at intranuclear punctate sites in non-complementing cells or in replication compartments in complementing cells, or viral DNA polymerase activity. Taken together, our results indicate that the RNA binding motif plays a crucial role in herpes simplex virus 1 DNA synthesis through a mechanism separate from effects on polymerase activity, thus identifying a distinct essential function of this motif with implications for hypotheses regarding its biochemical functions.
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Affiliation(s)
- Jessica L Lawler
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Committee on Virology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Shariya Terrell
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Donald M Coen
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Committee on Virology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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4
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Byareddy SN, Sharma K, Sachdev S, Reddy AS, Acharya A, Klaustermeier KM, Lorson CL, Singh K. Potential therapeutic targets for Mpox: the evidence to date. Expert Opin Ther Targets 2023; 27:419-431. [PMID: 37368464 PMCID: PMC10722886 DOI: 10.1080/14728222.2023.2230361] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/07/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
INTRODUCTION The global Mpox (MPX) disease outbreak caused by the Mpox virus (MPXV) in 2022 alarmed the World Health Organization (WHO) and health regulation agencies of individual countries leading to the declaration of MPX as a Public Health Emergency. Owing to the genetic similarities between smallpox-causing poxvirus and MPXV, vaccine JYNNEOS, and anti-smallpox drugs Brincidofovir and Tecovirimat were granted emergency use authorization by the United States Food and Drug Administration. The WHO also included cidofovir, NIOCH-14, and other vaccines as treatment options. AREAS COVERED This article covers the historical development of EUA-granted antivirals, resistance to these antivirals, and the projected impact of signature mutations on the potency of antivirals against currently circulating MPXV. Since a high prevalence of MPXV infections in individuals coinfected with HIV and MPXV, the treatment results among these individuals have been included. EXPERT OPINION All EUA-granted drugs have been approved for smallpox treatment. These antivirals show good potency against Mpox. However, conserved resistance mutation positions in MPXV and related poxviruses, and the signature mutations in the 2022 MPXV can potentially compromise the efficacy of the EUA-granted treatments. Therefore, MPXV-specific medications are required not only for the current but also for possible future outbreaks.
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Affiliation(s)
- Siddappa N Byareddy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | - Shrikesh Sachdev
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Athreya S. Reddy
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Arpan Acharya
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | - Christian L Lorson
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Kamal Singh
- Department of Pharmaceutical Chemistry, DPSRU, New Delhi-110017
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
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5
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Lisova AE, Baranovskiy AG, Morstadt LM, Babayeva ND, Tahirov TH. Efficient discrimination against RNA-containing primers by human DNA polymerase ε. Sci Rep 2022; 12:10163. [PMID: 35715491 PMCID: PMC9205888 DOI: 10.1038/s41598-022-14602-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/09/2022] [Indexed: 01/13/2023] Open
Abstract
DNA polymerase ε (Polε) performs bulk synthesis of DNA on the leading strand during genome replication. Polε binds two substrates, a template:primer and dNTP, and catalyzes a covalent attachment of dNMP to the 3' end of the primer. Previous studies have shown that Polε easily inserts and extends ribonucleotides, which may promote mutagenesis and genome instability. In this work, we analyzed the mechanisms of discrimination against RNA-containing primers by human Polε (hPolε), performing binding and kinetic studies at near-physiological salt concentration. Pre-steady-state kinetic studies revealed that hPolεCD extends RNA primers with approximately 3300-fold lower efficiency in comparison to DNA, and addition of one dNMP to the 3' end of an RNA primer increases activity 36-fold. Likewise, addition of one rNMP to the 3' end of a DNA primer reduces activity 38-fold. The binding studies conducted in the presence of 0.15 M NaCl revealed that human hPolεCD has low affinity to DNA (KD of 1.5 µM). Strikingly, a change of salt concentration from 0.1 M to 0.15 M reduces the stability of the hPolεCD/DNA complex by 25-fold. Upon template:primer binding, the incoming dNTP and magnesium ions make hPolε discriminative against RNA and chimeric RNA-DNA primers. In summary, our studies revealed that hPolε discrimination against RNA-containing primers is based on the following factors: incoming dNTP, magnesium ions, a steric gate for the primer 2'OH, and the rigid template:primer binding pocket near the catalytic site. In addition, we showed the importance of conducting functional studies at near-physiological salt concentration.
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Affiliation(s)
- Alisa E Lisova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Andrey G Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Lucia M Morstadt
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Nigar D Babayeva
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Tahir H Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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6
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Structural and Molecular Kinetic Features of Activities of DNA Polymerases. Int J Mol Sci 2022; 23:ijms23126373. [PMID: 35742812 PMCID: PMC9224347 DOI: 10.3390/ijms23126373] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 02/01/2023] Open
Abstract
DNA polymerases catalyze DNA synthesis during the replication, repair, and recombination of DNA. Based on phylogenetic analysis and primary protein sequences, DNA polymerases have been categorized into seven families: A, B, C, D, X, Y, and RT. This review presents generalized data on the catalytic mechanism of action of DNA polymerases. The structural features of different DNA polymerase families are described in detail. The discussion highlights the kinetics and conformational dynamics of DNA polymerases from all known polymerase families during DNA synthesis.
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7
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Baranovskiy AG, Babayeva ND, Lisova AE, Morstadt LM, Tahirov TH. Structural and functional insight into mismatch extension by human DNA polymerase α. Proc Natl Acad Sci U S A 2022; 119:e2111744119. [PMID: 35467978 PMCID: PMC9169922 DOI: 10.1073/pnas.2111744119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 03/08/2022] [Indexed: 12/11/2022] Open
Abstract
Human DNA polymerase α (Polα) does not possess proofreading ability and plays an important role in genome replication and mutagenesis. Polα extends the RNA primers generated by primase and provides a springboard for loading other replication factors. Here we provide the structural and functional analysis of the human Polα interaction with a mismatched template:primer. The structure of the human Polα catalytic domain in the complex with an incoming deoxycytidine triphosphate (dCTP) and the template:primer containing a T-C mismatch at the growing primer terminus was solved at a 2.9 Å resolution. It revealed the absence of significant distortions in the active site and in the conformation of the substrates, except the primer 3′-end. The T-C mismatch acquired a planar geometry where both nucleotides moved toward each other by 0.4 Å and 0.7 Å, respectively, and made one hydrogen bond. The binding studies conducted at a physiological salt concentration revealed that Polα has a low affinity to DNA and is not able to discriminate against a mispaired template:primer in the absence of deoxynucleotide triphosphate (dNTP). Strikingly, in the presence of cognate dNTP, Polα showed a more than 10-fold higher selectivity for a correct duplex versus a mismatched one. According to pre-steady-state kinetic studies, human Polα extends the T-C mismatch with a 249-fold lower efficiency due to reduction of the polymerization rate constant by 38-fold and reduced affinity to the incoming nucleotide by 6.6-fold. Thus, a mismatch at the postinsertion site affects all factors important for primer extension: affinity to both substrates and the rate of DNA polymerization.
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Affiliation(s)
- Andrey G. Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
| | - Nigar D. Babayeva
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
| | - Alisa E. Lisova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
| | - Lucia M. Morstadt
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
| | - Tahir H. Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
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8
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Wang J, Konigsberg WH. Two-Metal-Ion Catalysis: Inhibition of DNA Polymerase Activity by a Third Divalent Metal Ion. Front Mol Biosci 2022; 9:824794. [PMID: 35300112 PMCID: PMC8921852 DOI: 10.3389/fmolb.2022.824794] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/14/2022] [Indexed: 11/15/2022] Open
Abstract
Almost all DNA polymerases (pols) exhibit bell-shaped activity curves as a function of both pH and Mg2+ concentration. The pol activity is reduced when the pH deviates from the optimal value. When the pH is too low the concentration of a deprotonated general base (namely, the attacking 3′-hydroxyl of the 3′ terminal residue of the primer strand) is reduced exponentially. When the pH is too high the concentration of a protonated general acid (i.e., the leaving pyrophosphate group) is reduced. Similarly, the pol activity also decreases when the concentration of the divalent metal ions deviates from its optimal value: when it is too low, the binding of the two catalytic divalent metal ions required for the full activity is incomplete, and when it is too high a third divalent metal ion binds to pyrophosphate, keeping it in the replication complex longer and serving as a substrate for pyrophosphorylysis within the complex. Currently, there is a controversy about the role of the third metal ion which we will address in this review.
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9
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Morcinek-Orłowska J, Zdrojewska K, Węgrzyn A. Bacteriophage-Encoded DNA Polymerases-Beyond the Traditional View of Polymerase Activities. Int J Mol Sci 2022; 23:635. [PMID: 35054821 PMCID: PMC8775771 DOI: 10.3390/ijms23020635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/28/2021] [Accepted: 01/06/2022] [Indexed: 02/04/2023] Open
Abstract
DNA polymerases are enzymes capable of synthesizing DNA. They are involved in replication of genomes of all cellular organisms as well as in processes of DNA repair and genetic recombination. However, DNA polymerases can also be encoded by viruses, including bacteriophages, and such enzymes are involved in viral DNA replication. DNA synthesizing enzymes are grouped in several families according to their structures and functions. Nevertheless, there are examples of bacteriophage-encoded DNA polymerases which are significantly different from other known enzymes capable of catalyzing synthesis of DNA. These differences are both structural and functional, indicating a huge biodiversity of bacteriophages and specific properties of their enzymes which had to evolve under certain conditions, selecting unusual properties of the enzymes which are nonetheless crucial for survival of these viruses, propagating as special kinds of obligatory parasites. In this review, we present a brief overview on DNA polymerases, and then we discuss unusual properties of different bacteriophage-encoded enzymes, such as those able to initiate DNA synthesis using the protein-priming mechanisms or even start this process without any primer, as well as able to incorporate untypical nucleotides. Apart from being extremely interesting examples of biochemical biodiversity, bacteriophage-encoded DNA polymerases can also be useful tools in genetic engineering and biotechnology.
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Affiliation(s)
- Joanna Morcinek-Orłowska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (J.M.-O.); (K.Z.)
| | - Karolina Zdrojewska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (J.M.-O.); (K.Z.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland
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10
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Park J, Youn HS, An JY, Lee Y, Eom SH, Wang J. Structure of New Binary and Ternary DNA Polymerase Complexes From Bacteriophage RB69. Front Mol Biosci 2021; 8:704813. [PMID: 34869578 PMCID: PMC8639217 DOI: 10.3389/fmolb.2021.704813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/30/2021] [Indexed: 11/29/2022] Open
Abstract
DNA polymerase plays a critical role in passing the genetic information of any living organism to its offspring. DNA polymerase from enterobacteria phage RB69 (RB69pol) has both polymerization and exonuclease activities and has been extensively studied as a model system for B-family DNA polymerases. Many binary and ternary complex structures of RB69pol are known, and they all contain a single polymerase-primer/template (P/T) DNA complex. Here, we report a crystal structure of the exonuclease-deficient RB69pol with the P/T duplex in a dimeric form at a resolution of 2.2 Å. The structure includes one new closed ternary complex with a single divalent metal ion bound and one new open binary complex in the pre-insertion state with a vacant dNTP-binding pocket. These complexes suggest that initial binding of the correct dNTP in the open state is much weaker than expected and that initial binding of the second divalent metal ion in the closed state is also much weaker than measured. Additional conformational changes are required to convert these complexes to high-affinity states. Thus, the measured affinities for the correct incoming dNTP and divalent metal ions are average values from many conformationally distinctive states. Our structure provides new insights into the order of the complex assembly involving two divalent metal ions. The biological relevance of specific interactions observed between one RB69pol and the P/T duplex bound to the second RB69pol observed within this dimeric complex is discussed.
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Affiliation(s)
- Jongseo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea
| | - Hyung-Seop Youn
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,BIO R&D Center, Ingredient Business Unit, Daesang Corporation, Gyeonggi-do, Korea
| | - Jun Yop An
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Virocure Inc., Seoul, Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Metabolic Regulation Research Center, Korea Research Institute of BIoscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.,Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Department of Chemistry, GIST, Gwangju, Korea
| | - Jimin Wang
- Steitz Center for Structural Biology, GIST, Gwangju, South Korea.,Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
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11
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Abstract
Herpesviruses comprise a family of DNA viruses that cause a variety of human and veterinary diseases. During productive infection, mammalian, avian, and reptilian herpesviruses replicate their genomes using a set of conserved viral proteins that include a two subunit DNA polymerase. This enzyme is both a model system for family B DNA polymerases and a target for inhibition by antiviral drugs. This chapter reviews the structure, function, and mechanisms of the polymerase of herpes simplex viruses 1 and 2 (HSV), with only occasional mention of polymerases of other herpesviruses such as human cytomegalovirus (HCMV). Antiviral polymerase inhibitors have had the most success against HSV and HCMV. Detailed structural information regarding HSV DNA polymerase is available, as is much functional information regarding the activities of the catalytic subunit (Pol), which include a DNA polymerization activity that can utilize both DNA and RNA primers, a 3'-5' exonuclease activity, and other activities in DNA synthesis and repair and in pathogenesis, including some remaining to be biochemically defined. Similarly, much is known regarding the accessory subunit, which both resembles and differs from sliding clamp processivity factors such as PCNA, and the interactions of this subunit with Pol and DNA. Both subunits contribute to replication fidelity (or lack thereof). The availability of both pharmacologic and genetic tools not only enabled the initial identification of Pol and the pol gene, but has also helped dissect their functions. Nevertheless, important questions remain for this long-studied enzyme, which is still an attractive target for new drug discovery.
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12
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Abstract
Human herpesviruses are large double-stranded DNA viruses belonging to the Herpesviridae family. The main characteristics of these viruses are their ability to establish a lifelong latency into the host with a potential to reactivate periodically. Primary infections and reactivations with herpesviruses are responsible for a large spectrum of diseases and may result in severe complications in immunocompromised patients. The viral DNA polymerase is a key enzyme in the replicative cycle of herpesviruses, and the target of most antiviral agents (i.e., nucleoside, nucleotide and pyrophosphate analogs). However, long-term prophylaxis and treatment with these antivirals may lead to the emergence of drug-resistant isolates harboring mutations in genes encoding viral enzymes that phosphorylate drugs (nucleoside analogs) and/or DNA polymerases, with potential cross-resistance between the different analogs. Drug resistance mutations mainly arise in conserved regions of the polymerase and exonuclease functional domains of these enzymes. In the polymerase domain, mutations associated with resistance to nucleoside/nucleotide analogs may directly or indirectly affect drug binding or incorporation into the primer strand, or increase the rate of extension of DNA to overcome chain termination. In the exonuclease domain, mutations conferring resistance to nucleoside/nucleotide analogs may reduce the rate of excision of incorporated drug, or continue DNA elongation after drug incorporation without excision. Mutations associated with resistance to pyrophosphate analogs may alter drug binding or the conformational changes of the polymerase domain required for an efficient activity of the enzyme. Novel herpesvirus inhibitors with a potent antiviral activity against drug-resistant isolates are thus needed urgently.
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Affiliation(s)
| | - Guy Boivin
- CHU de Québec-Université Laval, Quebec City, QC, Canada.
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13
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Bocanegra R, Plaza G A I, Ibarra B. In vitro single-molecule manipulation studies of viral DNA replication. Enzymes 2021; 49:115-148. [PMID: 34696830 DOI: 10.1016/bs.enz.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Faithfull replication of genomic information relies on the coordinated activity of the multi-protein machinery known as the replisome. Several constituents of the replisome operate as molecular motors that couple thermal and chemical energy to a mechanical task. Over the last few decades, in vitro single-molecule manipulation techniques have been used to monitor and manipulate mechanically the activities of individual molecular motors involved in DNA replication with nanometer, millisecond, and picoNewton resolutions. These studies have uncovered the real-time kinetics of operation of these biological systems, the nature of their transient intermediates, and the processes by which they convert energy to work (mechano-chemistry), ultimately providing new insights into their inner workings of operation not accessible by ensemble assays. In this chapter, we describe two of the most widely used single-molecule manipulation techniques for the study of DNA replication, optical and magnetic tweezers, and their application in the study of the activities of proteins involved in viral DNA replication.
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Affiliation(s)
- Rebeca Bocanegra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Ismael Plaza G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain.
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14
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Sahoo M, N A, Baral PR, Klumpp S. Accuracy and speed of elongation in a minimal model of DNA replication. Phys Rev E 2021; 104:034417. [PMID: 34654207 DOI: 10.1103/physreve.104.034417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/08/2021] [Indexed: 11/07/2022]
Abstract
Being a dual purpose enzyme, the DNA polymerase is responsible for elongation of the newly formed DNA strand as well as cleaving the erroneous growth in case of a misincorporation. The efficiency of replication depends on the coordination of the polymerization and exonuclease activity of DNA polymerase. Here, we propose and analyze a minimal kinetic model of DNA replication and determine exact expressions for the velocity of elongation and the accuracy of replication. We first analyze the case without exonuclease activity. In that case, accuracy is determined by a kinetic competition between stepping and unbinding, with discrimination between correct and incorrect nucleotides in both transitions. We then include exonuclease activity and ask how different modes of additional discrimination in the exonuclease pathway can improve the accuracy while limiting the detrimental effect of exonuclease on the speed of replication. In this way, we ask how the kinetic parameters of the model have to be set to coordinate the two activities of the enzyme for high accuracy and high speed. The analysis also shows that the design of a replication system does not universally have to follow the speed-accuracy trade-off rule, although it does in the biologically realized parameter range. The accuracy of the process is mainly controlled by the crucial role of stepping after erroneous incorporation, which has impact on both polymerase and exonuclease activities of DNA polymerase.
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Affiliation(s)
- M Sahoo
- Department of Physics, University of Kerala, Kariavattom Campus 695581, India.,School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram-695551, India
| | - Arsha N
- Department of Physics, University of Kerala, Kariavattom Campus 695581, India
| | - P R Baral
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram-695551, India
| | - S Klumpp
- Institute for the Dynamics of Complex Systems, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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15
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Lo CY, Gao Y. DNA Helicase-Polymerase Coupling in Bacteriophage DNA Replication. Viruses 2021; 13:v13091739. [PMID: 34578319 PMCID: PMC8472574 DOI: 10.3390/v13091739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/28/2022] Open
Abstract
Bacteriophages have long been model systems to study the molecular mechanisms of DNA replication. During DNA replication, a DNA helicase and a DNA polymerase cooperatively unwind the parental DNA. By surveying recent data from three bacteriophage replication systems, we summarized the mechanistic basis of DNA replication by helicases and polymerases. Kinetic data have suggested that a polymerase or a helicase alone is a passive motor that is sensitive to the base-pairing energy of the DNA. When coupled together, the helicase-polymerase complex is able to unwind DNA actively. In bacteriophage T7, helicase and polymerase reside right at the replication fork where the parental DNA is separated into two daughter strands. The two motors pull the two daughter strands to opposite directions, while the polymerase provides a separation pin to split the fork. Although independently evolved and containing different replisome components, bacteriophage T4 replisome shares mechanistic features of Hel-Pol coupling that are similar to T7. Interestingly, in bacteriophages with a limited size of genome like Φ29, DNA polymerase itself can form a tunnel-like structure, which encircles the DNA template strand and facilitates strand displacement synthesis in the absence of a helicase. Studies on bacteriophage replication provide implications for the more complicated replication systems in bacteria, archaeal, and eukaryotic systems, as well as the RNA genome replication in RNA viruses.
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Affiliation(s)
| | - Yang Gao
- Correspondence: ; Tel.: +1-713-348-2619
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16
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Structure of an open conformation of T7 DNA polymerase reveals novel structural features regulating primer-template stabilization at the polymerization active site. Biochem J 2021; 478:2665-2679. [PMID: 34160020 DOI: 10.1042/bcj20200922] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 01/25/2023]
Abstract
The crystal structure of full-length T7 DNA polymerase in complex with its processivity factor thioredoxin and double-stranded DNA in the polymerization active site exhibits two novel structural motifs in family-A DNA polymerases: an extended β-hairpin at the fingers subdomain, that interacts with the DNA template strand downstream the primer-terminus, and a helix-loop-helix motif (insertion1) located between residues 102 to 122 in the exonuclease domain. The extended β-hairpin is involved in nucleotide incorporation on substrates with 5'-overhangs longer than 2 nt, suggesting a role in stabilizing the template strand into the polymerization domain. Our biochemical data reveal that insertion1 of the exonuclease domain makes stabilizing interactions that facilitate proofreading by shuttling the primer strand into the exonuclease active site. Overall, our studies evidence conservation of the 3'-5' exonuclease domain fold between family-A DNA polymerases and highlight the modular architecture of T7 DNA polymerase. Our data suggest that the intercalating β-hairpin guides the template-strand into the polymerization active site after the T7 primase-helicase unwinds the DNA double helix ameliorating the formation of secondary structures and decreasing the appearance of indels.
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17
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Jarillo J, Ibarra B, Cao-García FJ. DNA replication: In vitro single-molecule manipulation data analysis and models. Comput Struct Biotechnol J 2021; 19:3765-3778. [PMID: 34285777 PMCID: PMC8267548 DOI: 10.1016/j.csbj.2021.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/05/2022] Open
Abstract
Data analysis allows to extract information from the noisy single-molecule data. Models provide insight in the underlying biochemical processes. Ligands can activate or inhibit DNA replication and DNA unwinding.
DNA replication is a key biochemical process of the cell cycle. In the last years, analysis of in vitro single-molecule DNA replication events has provided new information that cannot be obtained with ensembles studies. Here, we introduce crucial techniques for the proper analysis and modelling of DNA replication in vitro single-molecule manipulation data. Specifically, we review some of the main methods to analyze and model the real-time kinetics of the two main molecular motors of the replisome: DNA polymerase and DNA helicase. Our goal is to facilitate access to and understanding of these techniques to promotetheir use in the study of DNA replication at the single-molecule level. A proper analysis of single-molecule data is crucial to obtain a detailed picture of, among others, the kinetics rates, equilibrium contants and conformational changes of the system under study. The techniques presented here have been used or can be adapted to study the operation of other proteins involved in nucleic acids metabolism.
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Affiliation(s)
- Javier Jarillo
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain
| | - Francisco Javier Cao-García
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain.,Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
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18
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Impact of Amino Acid Substitutions in Region II and Helix K of Herpes Simplex Virus 1 and Human Cytomegalovirus DNA Polymerases on Resistance to Foscarnet. Antimicrob Agents Chemother 2021; 65:e0039021. [PMID: 33875432 DOI: 10.1128/aac.00390-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Amino acid substitutions conferring resistance of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) to foscarnet (PFA) are located in the genes UL30 and UL54, respectively, encoding the DNA polymerase (pol). In this study, we analyzed the impact of substitutions located in helix K and region II that are involved in the conformational changes of the DNA pol. Theoretical substitutions were identified by sequences alignment of the helix K and region II of human herpesviruses (susceptible to PFA) and bacteriophages (resistant to PFA) and introduced in viral genomes by recombinant phenotyping. We characterized the susceptibility of HSV-1 and HCMV mutants to PFA. In UL30, the substitutions I619K (helix K), V715S, and A719T (both in region II) increased mean PFA 50% effective concentrations (EC50s) by 2.5-, 5.6-, and 2.0-fold, respectively, compared to the wild type (WT). In UL54, the substitution Q579I (helix K) conferred hypersusceptibility to PFA (0.17-fold change), whereas the substitutions Q697P, V715S, and A719T (all in region II) increased mean PFA EC50s by 3.8-, 2.8- and 2.5-fold, respectively, compared to the WT. These results were confirmed by enzymatic assays using recombinant DNA pol harboring these substitutions. Three-dimensional modeling suggests that substitutions conferring resistance/hypersusceptibility to PFA located in helix K and region II of UL30 and UL54 DNA pol favor an open/closed conformation of these enzymes, resulting in a lower/higher drug affinity for the proteins. Thus, this study shows that both regions of UL30 and UL54 DNA pol are involved in the conformational changes of these proteins and can influence the susceptibility of both viruses to PFA.
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19
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A patient with POLA1 splice variant expands the yet evolving phenotype of Van Esch O'Driscoll syndrome. Eur J Med Genet 2021; 64:104261. [PMID: 34119699 DOI: 10.1016/j.ejmg.2021.104261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/24/2021] [Accepted: 06/08/2021] [Indexed: 11/23/2022]
Abstract
Van Esch-O'Driscoll syndrome (VEODS) is a rare cause of syndromic X-linked intellectual disability characterised by short stature, microcephaly, variable degree of intellectual disability, and hypogonadotropic hypogonadism. To date, heterozygous hypomorphic variants in the gene encoding the DNA Polymerase α subunit, POLA1, have been observed in nine patients from five unrelated families with VEODS. We report a three-year-old child with VEODS having borderline intellectual disability due to a novel splice site variant causing exon 6 skipping and reduced POLA1 expression.
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20
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Piret J, Boivin G. Antiviral Drugs Against Herpesviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1322:1-30. [PMID: 34258735 DOI: 10.1007/978-981-16-0267-2_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The discovery of the nucleoside analogue, acyclovir, represented a milestone in the management of infections caused by herpes simplex virus and varicella-zoster virus. Ganciclovir, another nucleoside analogue, was then used for the management of systemic and organ-specific human cytomegalovirus diseases. The pyrophosphate analogue, foscarnet, and the nucleotide analogue, cidofovir, have been approved subsequently and constitute the second-line antiviral drugs. However, the viral DNA polymerase is the ultimate target of all these antiviral agents with a possible emergence of cross-resistance between these drugs. Recently, letermovir that targets the viral terminase complex was approved for the prophylaxis of human cytomegalovirus infections in hematopoietic stem cell transplant recipients. Other viral targets such as the protein kinase and the helicase-primase complex are also evaluated for the development of novel potent inhibitors against herpesviruses.
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Affiliation(s)
| | - Guy Boivin
- CHU de Québec-Laval University, Quebec City, QC, Canada.
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21
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Reha-Krantz LJ, Goodman MF. John W. (Jan) Drake: A Biochemical View of a Geneticist Par Excellence. Genetics 2020; 216:827-836. [PMID: 33268388 PMCID: PMC7768258 DOI: 10.1534/genetics.120.303813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/22/2020] [Indexed: 11/18/2022] Open
Abstract
John W. Drake died 02-02-2020, a mathematical palindrome, which he would have enjoyed, given his love of "word play and logic," as stated in his obituary and echoed by his family, friends, students, and colleagues. Many aspects of Jan's career have been reviewed previously, including his early years as a Caltech graduate student, and when he was editor-in-chief, with the devoted assistance of his wife Pam, of this journal for 15 impactful years. During his editorship, he raised the profile of GENETICS as the flagship journal of the Genetics Society of America and inspired and contributed to the creation of the Perspectives column, coedited by Jim Crow and William Dove. At the same time, Jan was building from scratch the Laboratory of Molecular Genetics on the newly established Research Triangle Park campus of the National Institute of Environmental Health Science, which he headed for 30 years. This commentary offers a unique perspective on Jan's legacy; we showcase Jan's 1969 benchmark discovery of antimutagenic T4 DNA polymerases and the research by three generations (and counting) of scientists whose research stems from that groundbreaking discovery. This is followed by a brief discussion of Jan's passion: his overriding interest in analyzing mutation rates across species. Several anecdotal stories are included to bring alive one of Jan's favorite phrases, "to think like a geneticist." We feature Jan's genetical approach to mutation studies, along with the biochemistry of DNA polymerase function, our area of expertise. But in the end, we acknowledge, as Jan did, that genetics, also known as in vivo biochemistry, prevails.
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Affiliation(s)
- Linda J Reha-Krantz
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Myron F Goodman
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
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22
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Abstract
We report here crystal structures of a reverse transcriptase RTX, which was evolved in vitro from the B family polymerase KOD, in complex with either a DNA duplex or an RNA-DNA hybrid. Compared with the apo, binary, and ternary complex structures of the original KOD polymerase, the 16 substitutions that result in the function of copying RNA to DNA do not change the overall protein structure. Only six substitutions occur at the substrate-binding surface, and the others change domain-domain interfaces in the polymerase to enable RNA-DNA hybrid binding and reverse transcription. Most notably, F587L at the Palm and Thumb interface stabilizes the open and apo conformation of the Thumb. The intrinsically flexible Thumb domain seems to play a major role in accommodating the RNA-DNA hybrid product distal to the active site. This is reminiscent of naturally occurring RNA-dependent DNA polymerases, including telomerase, which have a dramatically augmented Thumb domain, and of reverse transcriptase, which extends its Thumb with the RNase H domain.
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23
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Zhang L, Jiang D, Shi H, Wu M, Gan Q, Yang Z, Oger P. Characterization and application of a family B DNA polymerase from the hyperthermophilic and radioresistant euryarchaeon Thermococcus gammatolerans. Int J Biol Macromol 2020; 156:217-224. [PMID: 32229210 DOI: 10.1016/j.ijbiomac.2020.03.204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 03/07/2020] [Accepted: 03/24/2020] [Indexed: 11/19/2022]
Abstract
Thermococcus gammatolerans is anaerobic euryarchaeon which grows optimally at 88 °C and its genome encodes a family B DNA polymerase (Tga PolB). Herein, we cloned the gene of Tga PolB, expressed and purified the gene product, and characterized the enzyme biochemically. The recombinant Tga PolB can efficiently synthesize DNA at high temperature, and retain 93% activity after heated at 95 °C for 1.0 h, suggesting that the enzyme is thermostable. Furthermore, the optimal pH for the enzyme activity was measured to be 7.0-9.0. Tga PolB activity is dependent on a divalent cation, among which magnesium ion is optimal. NaCl at low concentration stimulates the enzyme activity but at high concentration inhibits enzyme activity. Interestingly, Tga PolB is able to efficiently bypass uracil in DNA, which is distinct from other archaeal family B DNA pols. By contrast, Tga PolB is halted by an AP site in DNA, as observed in other archaeal family B DNA polymerases. Furthermore, Tga PolB extends the mismatched ends with reduced efficiencies. The enzyme possesses 3'-5' exonuclease activity and this activity is inhibited by dNTPs. The DNA binding assays showed that Tga PolB can efficiently bind to ssDNA and primed DNA, and have a marked preference for primed DNA. Last, Tga PolB can be used in routine PCR.
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Affiliation(s)
- Likui Zhang
- Marine Science & Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Jiangsu Province 225127, China; Guangling College, Yangzhou University, China.
| | - Donghao Jiang
- Marine Science & Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Jiangsu Province 225127, China
| | - Haoqiang Shi
- Marine Science & Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Jiangsu Province 225127, China
| | - Mai Wu
- Marine Science & Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Jiangsu Province 225127, China
| | - Qi Gan
- Marine Science & Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Jiangsu Province 225127, China
| | - Zhihui Yang
- College of Plant Protection, Agricultural University of Hebei, Baoding, City, Hebei Province 071001, China.
| | - Philippe Oger
- Univ Lyon, INSA de Lyon, CNRS UMR 5240, Villeurbanne, France.
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24
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Chen X, Su S, Chen Y, Gao Y, Li Y, Shao Z, Zhang Y, Shao Q, Liu H, Li J, Ma J, Gan J. Structural studies reveal a ring-shaped architecture of deep-sea vent phage NrS-1 polymerase. Nucleic Acids Res 2020; 48:3343-3355. [PMID: 32016421 PMCID: PMC7102993 DOI: 10.1093/nar/gkaa071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 11/23/2022] Open
Abstract
NrS-1 is the first known phage that can infect Epsilonproteobacteria, one of the predominant primary producers in the deep-sea hydrothermal vent ecosystems. NrS-1 polymerase is a multidomain enzyme and is one key component of the phage replisome. The N-terminal Prim/Pol and HBD domains are responsible for DNA polymerization and de novo primer synthesis activities of NrS-1 polymerase. However, the structure and function of the C-terminus (CTR) of NrS-1 polymerase are poorly understood. Here, we report two crystal structures, showing that NrS-1 CTR adopts one unique hexameric ring-shaped conformation. Although the central helicase domain of NrS-1 CTR shares structural similarity with the superfamily III helicases, the folds of the Head and Tail domains are completely novel. Via mutagenesis and in vitro biochemical analysis, we identified many residues important for the helicase and polymerization activities of NrS-1 polymerase. In addition to NrS-1 polymerase, our study may also help us identify and understand the functions of multidomain polymerases expressed by many NrS-1 related phages.
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Affiliation(s)
- Xi Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China.,State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shichen Su
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yiqing Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yanqing Gao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yangyang Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Zhiwei Shao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yixi Zhang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Qiyuan Shao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Hehua Liu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jixi Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jianhua Gan
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Public Health Clinical Center, School of Life Sciences, Fudan University, Shanghai 200438, China
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25
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Foley MC, Couto L, Rauf S, Boyke A. Insights into DNA polymerase δ’s mechanism for accurate DNA replication. J Mol Model 2019; 25:80. [DOI: 10.1007/s00894-019-3957-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/05/2019] [Indexed: 11/28/2022]
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26
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Del Prado A, Rodríguez I, Lázaro JM, Moreno-Morcillo M, de Vega M, Salas M. New insights into the coordination between the polymerization and 3'-5' exonuclease activities in ϕ29 DNA polymerase. Sci Rep 2019; 9:923. [PMID: 30696917 PMCID: PMC6351526 DOI: 10.1038/s41598-018-37513-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/06/2018] [Indexed: 11/09/2022] Open
Abstract
Bacteriophage ϕ29 DNA polymerase has two activities: DNA polymerization and 3′-5′ exonucleolysis governed by catalytic sites present in two structurally distant domains. These domains must work together to allow the correct replication of the template and to prevent the accumulation of errors in the newly synthesized DNA strand. ϕ29 DNA polymerase is endowed with a high processivity and strand displacement capacity together with a high fidelity. Previous studies of its crystallographic structure suggested possible interactions of residues of the exonuclease domain like the Gln180 with the fingers subdomain, or water mediated and direct hydrogen bond by the polar groups of residues Tyr101 and Thr189 that could stabilize DNA binding. To analyse their functional importance for the exonuclease activity of ϕ29 DNA polymerase we engineered mutations to encode amino acid substitutions. Our results confirm that both residues, Tyr101 and Thr189 are involved in the 3′-5′ exonuclease activity and in binding the dsDNA. In addition, Tyr101 is playing a role in processivity and Thr189 is an important determinant in the fidelity of the DNA polymerase. On the other hand, the biochemical characterization of the mutant derivatives of residue Gln180 showed how the mutations introduced enhanced the 3′-5′ exonuclease activity of the enzyme. A potential structural conformation prone to degrade the substrate is discussed.
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Affiliation(s)
- Alicia Del Prado
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Irene Rodríguez
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - José María Lázaro
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - María Moreno-Morcillo
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Miguel de Vega
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Margarita Salas
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain.
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27
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Parkash V, Kulkarni Y, Ter Beek J, Shcherbakova PV, Kamerlin SCL, Johansson E. Structural consequence of the most frequently recurring cancer-associated substitution in DNA polymerase ε. Nat Commun 2019; 10:373. [PMID: 30670696 PMCID: PMC6342957 DOI: 10.1038/s41467-018-08114-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 12/12/2018] [Indexed: 11/21/2022] Open
Abstract
The most frequently recurring cancer-associated DNA polymerase ε (Pol ε) mutation is a P286R substitution in the exonuclease domain. While originally proposed to increase genome instability by disrupting exonucleolytic proofreading, the P286R variant was later found to be significantly more pathogenic than Pol ε proofreading deficiency per se. The mechanisms underlying its stronger impact remained unclear. Here we report the crystal structure of the yeast orthologue, Pol ε−P301R, complexed with DNA and an incoming dNTP. Structural changes in the protein are confined to the exonuclease domain, with R301 pointing towards the exonuclease site. Molecular dynamics simulations suggest that R301 interferes with DNA binding to the exonuclease site, an outcome not observed with the exonuclease-inactive Pol ε−D290A,E292A variant lacking the catalytic residues. These results reveal a distinct mechanism of exonuclease inactivation by the P301R substitution and a likely basis for its dramatically higher mutagenic and tumorigenic effects. Mutations in the human POLE gene are associated with tumours with high mutational loads. Here the authors provide a structural rationale for the mutagenic activity of the cancer-associated DNA polymerase ε P286R variant.
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Affiliation(s)
- Vimal Parkash
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-90187, Sweden
| | - Yashraj Kulkarni
- Department of Chemistry - BMC, Uppsala University, Box 576, Uppsala, S-751 23, Sweden
| | - Josy Ter Beek
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-90187, Sweden
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | | | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-90187, Sweden.
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28
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In Situ Structures of the Polymerase Complex and RNA Genome Show How Aquareovirus Transcription Machineries Respond to Uncoating. J Virol 2018; 92:JVI.00774-18. [PMID: 30068643 DOI: 10.1128/jvi.00774-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/19/2018] [Indexed: 12/28/2022] Open
Abstract
Reoviruses carry out genomic RNA transcription within intact viruses to synthesize plus-sense RNA strands, which are capped prior to their release as mRNA. The in situ structures of the transcriptional enzyme complex (TEC) containing the RNA-dependent RNA polymerase (RdRp) and NTPase are known for the single-layered reovirus cytoplasmic polyhedrosis virus (CPV), but not for multilayered reoviruses, such as aquareoviruses (ARV), which possess a primed stage that CPV lacks. Consequently, how the RNA genome and TEC respond to priming in reoviruses is unknown. Here, we determined the near-atomic-resolution asymmetric structure of ARV in the primed state by cryo-electron microscopy (cryo-EM), revealing the in situ structures of 11 TECs inside each capsid and their interactions with the 11 surrounding double-stranded RNA (dsRNA) genome segments and with the 120 enclosing capsid shell protein (CSP) VP3 subunits. The RdRp VP2 and the NTPase VP4 associate with each other and with capsid vertices; both bind RNA in multiple locations, including a novel C-terminal domain of VP4. Structural comparison between the primed and quiescent states showed translocation of the dsRNA end from the NTPase to the RdRp during priming. The RNA template channel was open in both states, suggesting that channel blocking is not a regulating mechanism between these states in ARV. Instead, the NTPase C-terminal domain appears to regulate RNA translocation between the quiescent and primed states. Taking the data together, dsRNA viruses appear to have adapted divergent mechanisms to regulate genome transcription while retaining similar mechanisms to coassemble their genome segments, TEC, and capsid proteins into infectious virions.IMPORTANCE Viruses in the family Reoviridae are characterized by the ability to endogenously synthesize nascent RNA within the virus. However, the mechanisms for assembling their RNA genomes with transcriptional enzymes into a multilayered virion and for priming such a virion for transcription are poorly understood. By cryo-EM and novel asymmetric reconstruction, we determined the atomic structure of the transcription complex inside aquareoviruses (ARV) that are primed for infection. The transcription complex is anchored by the N-terminal segments of enclosing capsid proteins and contains an NTPase and a polymerase. The NTPase has a newly discovered domain that translocates the 5' end of plus-sense RNA in segmented dsRNA genomes from the NTPase to polymerase VP2 when the virus changes from the inactive (quiescent) to the primed state. Conformation changes in capsid proteins and transcriptional complexes suggest a mechanism for relaying information from the outside to the inside of the virus during priming.
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29
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Redrejo-Rodríguez M, Ordóñez CD, Berjón-Otero M, Moreno-González J, Aparicio-Maldonado C, Forterre P, Salas M, Krupovic M. Primer-Independent DNA Synthesis by a Family B DNA Polymerase from Self-Replicating Mobile Genetic Elements. Cell Rep 2018; 21:1574-1587. [PMID: 29117562 PMCID: PMC5695915 DOI: 10.1016/j.celrep.2017.10.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 09/19/2017] [Accepted: 10/11/2017] [Indexed: 01/06/2023] Open
Abstract
Family B DNA polymerases (PolBs) play a central role during replication of viral and cellular chromosomes. Here, we report the discovery of a third major group of PolBs, which we denote primer-independent PolB (piPolB), that might be a link between the previously known protein-primed and RNA/DNA-primed PolBs. PiPolBs are encoded by highly diverse mobile genetic elements, pipolins, integrated in the genomes of diverse bacteria and also present as circular plasmids in mitochondria. Biochemical characterization showed that piPolB displays efficient DNA polymerization activity that can use undamaged and damaged templates and is endowed with proofreading and strand displacement capacities. Remarkably, the protein is also capable of template-dependent de novo DNA synthesis, i.e., DNA-priming activity, thereby breaking the long-standing dogma that replicative DNA polymerases require a pre-existing primer for DNA synthesis. We suggest that piPolBs are involved in self-replication of pipolins and may also contribute to bacterial DNA damage tolerance.
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Affiliation(s)
- Modesto Redrejo-Rodríguez
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
| | - Carlos D Ordóñez
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - Mónica Berjón-Otero
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - Juan Moreno-González
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - Cristian Aparicio-Maldonado
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - Patrick Forterre
- Institut Pasteur, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Paris, France
| | - Margarita Salas
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
| | - Mart Krupovic
- Institut Pasteur, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Paris, France.
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30
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Raper AT, Reed AJ, Suo Z. Kinetic Mechanism of DNA Polymerases: Contributions of Conformational Dynamics and a Third Divalent Metal Ion. Chem Rev 2018; 118:6000-6025. [DOI: 10.1021/acs.chemrev.7b00685] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Austin T. Raper
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andrew J. Reed
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Zucai Suo
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
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31
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The N Terminus of Autographa californica Multiple Nucleopolyhedrovirus DNA Polymerase Is Required for Efficient Viral DNA Replication and Virus and Occlusion Body Production. J Virol 2018; 92:JVI.00398-18. [PMID: 29563284 DOI: 10.1128/jvi.00398-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 02/06/2023] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) DNA polymerase (DNApol) plays a crucial role in viral DNA synthesis, and the N terminus (residues 1 to 186) is highly conserved in the baculovirus DNApol family. However, the functional role of the N terminus of DNApol has not yet been characterized. Here we report a functional analysis of the AcMNPV DNApol N terminus. We truncated the DNApol N terminus to construct truncation mutants Bac-GFP-PolΔ64, Bac-GFP-PolΔ110, and Bac-GFP-PolΔ186, which lack 64, 110, and 186 N-terminal residues, respectively. Although the truncation mutants rescued viral DNA synthesis and infectious virus production, the level of DNA replication decreased, and Bac-GFP-PolΔ64, Bac-GFP-PolΔ110, and Bac-GFP-PolΔ186 showed 10-fold, 89-fold, and 891-fold reductions in infectious viral yield compared to that of the wild-type repair virus, respectively. Production of occlusion bodies was compromised for all truncation mutants. Further bioinformatic analysis showed that the first 64 amino acids (aa) at the extreme N terminus contains a conserved α(-helix)-β(-sheet)-β-β secondary-structure region, and further downstream sequence from aa 67 to 186 is comprised of four conserved sequence motifs. Multiple alanine point substitutions in the α-β-β-β structure region or the four sequence motifs in the N terminus impaired viral DNA replication and resulted in reduction of virus yield and occlusion body production. Together, our results suggested that the secondary structure and four conserved motifs within the N terminus of AcMNPV DNApol are important for viral DNA synthesis, infectious virus yield, and production of occlusion bodies.IMPORTANCE DNA polymerase (DNApol) is highly conserved in all baculoviruses and is required for viral DNA replication. The N terminus is one of the highly conserved regions of baculovirus DNApols. Our results showed that the N terminus of baculovirus DNA polymerase plays an important role in efficient viral DNA synthesis and infectious virus yield and production of occlusion bodies. We identified five features, including a highly conserved secondary structure and four conserved amino acid motifs, in the AcMNPV DNApol N terminus, all of which are important for efficient viral DNA synthesis, infectious virus yield, and production of occlusion bodies.
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32
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Baranovskiy AG, Duong VN, Babayeva ND, Zhang Y, Pavlov YI, Anderson KS, Tahirov TH. Activity and fidelity of human DNA polymerase α depend on primer structure. J Biol Chem 2018; 293:6824-6843. [PMID: 29555682 DOI: 10.1074/jbc.ra117.001074] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/09/2018] [Indexed: 12/13/2022] Open
Abstract
DNA polymerase α (Polα) plays an important role in genome replication. In a complex with primase, Polα synthesizes chimeric RNA-DNA primers necessary for replication of both chromosomal DNA strands. During RNA primer extension with deoxyribonucleotides, Polα needs to use double-stranded helical substrates having different structures. Here, we provide a detailed structure-function analysis of human Polα's interaction with dNTPs and DNA templates primed with RNA, chimeric RNA-DNA, or DNA. We report the crystal structures of two ternary complexes of the Polα catalytic domain containing dCTP, a DNA template, and either a DNA or an RNA primer. Unexpectedly, in the ternary complex with a DNA:DNA duplex and dCTP, the "fingers" subdomain of Polα is in the open conformation. Polα induces conformational changes in the DNA and hybrid duplexes to produce the universal double helix form. Pre-steady-state kinetic studies indicated for both duplex types that chemical catalysis rather than product release is the rate-limiting step. Moreover, human Polα extended DNA primers with higher efficiency but lower processivity than it did with RNA and chimeric primers. Polα has a substantial propensity to make errors during DNA synthesis, and we observed that its fidelity depends on the type of sugar at the primer 3'-end. A detailed structural comparison of Polα with other replicative DNA polymerases disclosed common features and some differences, which may reflect the specialization of each polymerase in genome replication.
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Affiliation(s)
- Andrey G Baranovskiy
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Vincent N Duong
- the Departments of Pharmacology and Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510
| | - Nigar D Babayeva
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Yinbo Zhang
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
| | - Youri I Pavlov
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and.,the Departments of Biochemistry and Molecular Biology, Pathology and Microbiology, and Genetics and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska 68198 and
| | - Karen S Anderson
- the Departments of Pharmacology and Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510
| | - Tahir H Tahirov
- From the Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, and
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33
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Noncatalytic aspartate at the exonuclease domain of proofreading DNA polymerases regulates both degradative and synthetic activities. Proc Natl Acad Sci U S A 2018. [PMID: 29531047 DOI: 10.1073/pnas.1718787115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Most replicative DNA polymerases (DNAPs) are endowed with a 3'-5' exonuclease activity to proofread the polymerization errors, governed by four universally conserved aspartate residues belonging to the Exo I, Exo II, and Exo III motifs. These residues coordinate the two metal ions responsible for the hydrolysis of the last phosphodiester bond of the primer strand. Structural alignment of the conserved exonuclease domain of DNAPs from families A, B, and C has allowed us to identify an additional and invariant aspartate, located between motifs Exo II and Exo III. The importance of this aspartate has been assessed by site-directed mutagenesis at the corresponding Asp121 of the family B ϕ29 DNAP. Substitution of this residue by either glutamate or alanine severely impaired the catalytic efficiency of the 3'-5' exonuclease activity, both on ssDNA and dsDNA. The polymerization activity of these mutants was also affected due to a defective translocation following nucleotide incorporation. Alanine substitution for the homologous Asp90 in family A T7 DNAP showed essentially the same phenotype as ϕ29 DNAP mutant D121A. This functional conservation, together with a close inspection of ϕ29 DNAP/DNA complexes, led us to conclude a pivotal role for this aspartate in orchestrating the network of interactions required during internal proofreading of misinserted nucleotides.
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34
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Fidelity of DNA replication-a matter of proofreading. Curr Genet 2018; 64:985-996. [PMID: 29500597 PMCID: PMC6153641 DOI: 10.1007/s00294-018-0820-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 02/27/2018] [Accepted: 02/28/2018] [Indexed: 01/29/2023]
Abstract
DNA that is transmitted to daughter cells must be accurately duplicated to maintain genetic integrity and to promote genetic continuity. A major function of replicative DNA polymerases is to replicate DNA with the very high accuracy. The fidelity of DNA replication relies on nucleotide selectivity of replicative DNA polymerase, exonucleolytic proofreading, and postreplicative DNA mismatch repair (MMR). Proofreading activity that assists most of the replicative polymerases is responsible for removal of incorrectly incorporated nucleotides from the primer terminus before further primer extension. It is estimated that proofreading improves the fidelity by a 2–3 orders of magnitude. The primer with the incorrect terminal nucleotide has to be moved to exonuclease active site, and after removal of the wrong nucleotide must be transferred back to polymerase active site. The mechanism that allows the transfer of the primer between pol and exo site is not well understood. While defects in MMR are well known to be linked with increased cancer incidence only recently, the replicative polymerases that have alterations in the exonuclease domain have been associated with some sporadic and hereditary human cancers. In this review, we would like to emphasize the importance of proofreading (3′-5′ exonuclease activity) in the fidelity of DNA replication and to highlight what is known about switching from polymerase to exonuclease active site.
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35
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General misincorporation frequency: Re-evaluation of the fidelity of DNA polymerases. Biochem Biophys Res Commun 2018; 496:1076-1081. [DOI: 10.1016/j.bbrc.2018.01.135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 01/21/2018] [Indexed: 01/07/2023]
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36
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Ralec C, Henry E, Lemor M, Killelea T, Henneke G. Calcium-driven DNA synthesis by a high-fidelity DNA polymerase. Nucleic Acids Res 2017; 45:12425-12440. [PMID: 29040737 PMCID: PMC5716173 DOI: 10.1093/nar/gkx927] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/04/2017] [Indexed: 11/14/2022] Open
Abstract
Divalent metal ions, usually Mg2+, are required for both DNA synthesis and proofreading functions by DNA polymerases (DNA Pol). Although used as a non-reactive cofactor substitute for binding and crystallographic studies, Ca2+ supports DNA polymerization by only one DNA Pol, Dpo4. Here, we explore whether Ca2+-driven catalysis might apply to high-fidelity (HiFi) family B DNA Pols. The consequences of replacing Mg2+ by Ca2+ on base pairing at the polymerase active site as well as the editing of terminal nucleotides at the exonuclease active site of the archaeal Pyrococcus abyssi DNA Pol (PabPolB) are characterized and compared to other (families B, A, Y, X, D) DNA Pols. Based on primer extension assays, steady-state kinetics and ion-chased experiments, we demonstrate that Ca2+ (and other metal ions) activates DNA synthesis by PabPolB. While showing a slower rate of phosphodiester bond formation, nucleotide selectivity is improved over that of Mg2+. Further mechanistic studies show that the affinities for primer/template are higher in the presence of Ca2+ and reinforced by a correct incoming nucleotide. Conversely, no exonuclease degradation of the terminal nucleotides occurs with Ca2+. Evolutionary and mechanistic insights among DNA Pols are thus discussed.
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Affiliation(s)
- Céline Ralec
- Ifremer, Centre de Brest, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,CNRS, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,Université de Brest Occidentale, UBO, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France
| | - Etienne Henry
- Ifremer, Centre de Brest, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,CNRS, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,Université de Brest Occidentale, UBO, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France
| | - Mélanie Lemor
- Ifremer, Centre de Brest, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,CNRS, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,Université de Brest Occidentale, UBO, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France
| | - Tom Killelea
- Ifremer, Centre de Brest, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,CNRS, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,Université de Brest Occidentale, UBO, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France
| | - Ghislaine Henneke
- Ifremer, Centre de Brest, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,CNRS, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France.,Université de Brest Occidentale, UBO, LM2E, UMR 6197, Technopole Brest-Iroise, 29280 Plouzané, France
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37
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Crystal structures of ternary complexes of archaeal B-family DNA polymerases. PLoS One 2017; 12:e0188005. [PMID: 29211756 PMCID: PMC5718519 DOI: 10.1371/journal.pone.0188005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 10/30/2017] [Indexed: 01/04/2023] Open
Abstract
Archaeal B-family polymerases drive biotechnology by accepting a wide substrate range of chemically modified nucleotides. By now no structural data for archaeal B-family DNA polymerases in a closed, ternary complex are available, which would be the basis for developing next generation nucleotides. We present the ternary crystal structures of KOD and 9°N DNA polymerases complexed with DNA and the incoming dATP. The structures reveal a third metal ion in the active site, which was so far only observed for the eukaryotic B-family DNA polymerase δ and no other B-family DNA polymerase. The structures reveal a wide inner channel and numerous interactions with the template strand that provide space for modifications within the enzyme and may account for the high processivity, respectively. The crystal structures provide insights into the superiority over other DNA polymerases concerning the acceptance of modified nucleotides.
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38
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Tarbouriech N, Ducournau C, Hutin S, Mas PJ, Man P, Forest E, Hart DJ, Peyrefitte CN, Burmeister WP, Iseni F. The vaccinia virus DNA polymerase structure provides insights into the mode of processivity factor binding. Nat Commun 2017; 8:1455. [PMID: 29129932 PMCID: PMC5682278 DOI: 10.1038/s41467-017-01542-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 09/26/2017] [Indexed: 11/12/2022] Open
Abstract
Vaccinia virus (VACV), the prototype member of the Poxviridae, replicates in the cytoplasm of an infected cell. The catalytic subunit of the DNA polymerase E9 binds the heterodimeric processivity factor A20/D4 to form the functional polymerase holoenzyme. Here we present the crystal structure of full-length E9 at 2.7 Å resolution that permits identification of important poxvirus-specific structural insertions. One insertion in the palm domain interacts with C-terminal residues of A20 and thus serves as the processivity factor-binding site. This is in strong contrast to all other family B polymerases that bind their co-factors at the C terminus of the thumb domain. The VACV E9 structure also permits rationalization of polymerase inhibitor resistance mutations when compared with the closely related eukaryotic polymerase delta–DNA complex. The catalytic subunit E9 of the vaccinia virus DNA polymerase forms a functional polymerase holoenzyme by interacting with the heterodimeric processivity factor A20/D4. Here the authors present the structure of full-length E9 and show that an insertion within its palm domain binds A20, in a mode different from other family B polymerases.
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Affiliation(s)
- Nicolas Tarbouriech
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Corinne Ducournau
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny-sur-Orge Cedex, France
| | - Stephanie Hutin
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Philippe J Mas
- Integrated Structural Biology Grenoble (ISBG) CNRS, CEA, Université Grenoble Alpes, EMBL, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Petr Man
- BioCeV-Institute of Microbiology, Czech Academy of Sciences, Prumyslova 595, 252 50, Vestec, Czech Republic.,Faculty of Science, Charles University, Hlavova 8, 128 43, Prague 2, Czech Republic
| | - Eric Forest
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Darren J Hart
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Christophe N Peyrefitte
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny-sur-Orge Cedex, France.,Emerging Pathogens Laboratory, Fondation Mérieux, 21 Avenue Tony Garnier, 69007, Lyon, France
| | - Wim P Burmeister
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Frédéric Iseni
- Unité de Virologie, Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny-sur-Orge Cedex, France.
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39
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Benkovic SJ, Spiering MM. Understanding DNA replication by the bacteriophage T4 replisome. J Biol Chem 2017; 292:18434-18442. [PMID: 28972188 DOI: 10.1074/jbc.r117.811208] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The T4 replisome has provided a unique opportunity to investigate the intricacies of DNA replication. We present a comprehensive review of this system focusing on the following: its 8-protein composition, their individual and synergistic activities, and assembly in vitro and in vivo into a replisome capable of coordinated leading/lagging strand DNA synthesis. We conclude with a brief comparison with other replisomes with emphasis on how coordinated DNA replication is achieved.
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Affiliation(s)
- Stephen J Benkovic
- From the Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Michelle M Spiering
- From the Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802
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40
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Variants of sequence family B Thermococcus kodakaraensis DNA polymerase with increased mismatch extension selectivity. PLoS One 2017; 12:e0183623. [PMID: 28832623 PMCID: PMC5568139 DOI: 10.1371/journal.pone.0183623] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/08/2017] [Indexed: 12/01/2022] Open
Abstract
Fidelity and selectivity of DNA polymerases are critical determinants for the biology of life, as well as important tools for biotechnological applications. DNA polymerases catalyze the formation of DNA strands by adding deoxynucleotides to a primer, which is complementarily bound to a template. To ensure the integrity of the genome, DNA polymerases select the correct nucleotide and further extend the nascent DNA strand. Thus, DNA polymerase fidelity is pivotal for ensuring that cells can replicate their genome with minimal error. DNA polymerases are, however, further optimized for more specific biotechnological or diagnostic applications. Here we report on the semi-rational design of mutant libraries derived by saturation mutagenesis at single sites of a 3’-5’-exonuclease deficient variant of Thermococcus kodakaraensis DNA polymerase (KOD pol) and the discovery for variants with enhanced mismatch extension selectivity by screening. Sites of potential interest for saturation mutagenesis were selected by their proximity to primer or template strands. The resulting libraries were screened via quantitative real-time PCR. We identified three variants with single amino acid exchanges—R501C, R606Q, and R606W—which exhibited increased mismatch extension selectivity. These variants were further characterized towards their potential in mismatch discrimination. Additionally, the identified enzymes were also able to differentiate between cytosine and 5-methylcytosine. Our results demonstrate the potential in characterizing and developing DNA polymerases for specific PCR based applications in DNA biotechnology and diagnostics.
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41
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Abstract
The fidelity of DNA replication is determined by many factors, here simplified as the contribution of the DNA polymerase (nucleotide selectivity and proofreading), mismatch repair, a balanced supply of nucleotides, and the condition of the DNA template (both in terms of sequence context and the presence of DNA lesions). This review discusses the contribution and interplay between these factors to the overall fidelity of DNA replication.
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Affiliation(s)
- Rais A Ganai
- Department of Medical Biochemistry and Biophysics, Umeå University, SE 901 87 Umeå, Sweden; Howard Hughes Medical Institute, Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NY 10016, USA
| | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE 901 87 Umeå, Sweden.
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42
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Chen G, Fang Y, Wu L, Yan Q, Krell PJ, Feng G. A betabaculovirus DNA polymerase cannot substitute for the DNA polymerase of the alphabaculovirus Autographa californica nucleopolyhedrovirus. Arch Virol 2017; 162:3487-3492. [PMID: 28730520 DOI: 10.1007/s00705-017-3468-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/15/2017] [Indexed: 01/23/2023]
Abstract
DNA polymerase (DNApol) is present in all baculoviruses and plays a crucial role in viral DNA replication. Previously we showed that the DNApol of the alphabaculovirus group II Spodoptera litura nucleopolyhedrovirus (SpltNPV) could partially substitute for the DNApol of a group I alphabaculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However, it is not known if a betabaculovirus DNApol could subsititute for the alphabaculovirus DNApol in AcMNPV. In this report, DNApol of the betabaculovirus Pieris rapae granulovirus (PiraGV) was inserted into a dnapol-null AcMNPV bacmid, creating Bac-AcΔpol:PrPol. The repair virus did not spread to neighboring cells; virus growth curve and real-time PCR revealed that the PiraGV dnapol substitution abrogated AcMNPV DNA replication and virus production. Immunofluorescence microscopy showed that PiraGV DNApol could be expressed and localized to the nucleus. Collectively, our results suggested that the alphabaculovirus AcMNPV DNApol could not be replaced by a DNApol from the betabaculovirus, PiraGV.
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Affiliation(s)
- Guoqing Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, China
| | - Yang Fang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, China
| | - Lijuan Wu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, China
| | - Qing Yan
- China National Rice Research Institute, Hangzhou, 311400, China
| | - Peter J Krell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Guozhong Feng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, China.
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43
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A Comparative Analysis of Translesion DNA Synthesis Catalyzed by a High-Fidelity DNA Polymerase. J Mol Biol 2017; 429:2308-2323. [PMID: 28601494 DOI: 10.1016/j.jmb.2017.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/01/2017] [Accepted: 06/01/2017] [Indexed: 11/20/2022]
Abstract
Translesion DNA synthesis (TLS) is the ability of DNA polymerases to incorporate nucleotides opposite and beyond damaged DNA. TLS activity is an important risk factor for the initiation and progression of genetic diseases such as cancer. In this study, we evaluate the ability of a high-fidelity DNA polymerase to perform TLS with 8-oxo-guanine (8-oxo-G), a highly pro-mutagenic DNA lesion formed by reactive oxygen species. Results of kinetic studies monitoring the incorporation of modified nucleotide analogs demonstrate that the binding affinity of the incoming dNTP is controlled by the overall hydrophobicity of the nucleobase. However, the rate constant for the polymerization step is regulated by hydrogen-bonding interactions made between the incoming nucleotide with 8-oxo-G. Results generated here for replicating the miscoding 8-oxo-G are compared to those published for the replication of the non-instructional abasic site. During the replication of both lesions, binding of the nucleotide substrate is controlled by energetics associated with nucleobase desolvation, whereas the rate constant for the polymerization step is influenced by the physical nature of the DNA lesion, that is, miscoding versus non-instructional. Collectively, these studies highlight the importance of nucleobase desolvation as a key physical feature that enhances the misreplication of structurally diverse DNA lesions.
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Zarrouk K, Piret J, Boivin G. Herpesvirus DNA polymerases: Structures, functions and inhibitors. Virus Res 2017; 234:177-192. [PMID: 28153606 DOI: 10.1016/j.virusres.2017.01.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/10/2017] [Accepted: 01/22/2017] [Indexed: 11/25/2022]
Abstract
Human herpesviruses are large double-stranded DNA viruses belonging to the Herpesviridae family. These viruses have the ability to establish lifelong latency into the host and to periodically reactivate. Primary infections and reactivations of herpesviruses cause a large spectrum of diseases and may lead to severe complications in immunocompromised patients. The viral DNA polymerase is a key enzyme in the lytic phase of the infection by herpesviruses. This review focuses on the structures and functions of viral DNA polymerases of herpes simplex virus (HSV) and human cytomegalovirus (HCMV). DNA polymerases of HSV (UL30) and HCMV (UL54) belong to B family DNA polymerases with which they share seven regions of homology numbered I to VII as well as a δ-region C which is homologous to DNA polymerases δ. These DNA polymerases are multi-functional enzymes exhibiting polymerase, 3'-5' exonuclease proofreading and ribonuclease H activities. Furthermore, UL30 and UL54 DNA polymerases form a complex with UL42 and UL44 processivity factors, respectively. The mechanisms involved in their polymerisation activity have been elucidated based on structural analyses of the DNA polymerase of bacteriophage RB69 crystallized under different conformations, i.e. the enzyme alone or in complex with DNA and with both DNA and incoming nucleotide. All antiviral agents currently used for the prevention or treatment of HSV and HCMV infections target the viral DNA polymerases. However, long-term administration of these antivirals may lead to the emergence of drug-resistant isolates harboring mutations in genes encoding viral enzymes that phosphorylate drugs (i.e., nucleoside analogues) and/or DNA polymerases.
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Affiliation(s)
- Karima Zarrouk
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada
| | - Jocelyne Piret
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada
| | - Guy Boivin
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada.
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Song YS, Shu YG, Zhou X, Ou-Yang ZC, Li M. Proofreading of DNA polymerase: a new kinetic model with higher-order terminal effects. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:025101. [PMID: 27842005 DOI: 10.1088/0953-8984/29/2/025101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The fidelity of DNA replication by DNA polymerase (DNAP) has long been an important issue in biology. While numerous experiments have revealed details of the molecular structure and working mechanism of DNAP which consists of both a polymerase site and an exonuclease (proofreading) site, there were quite a few theoretical studies on the fidelity issue. The first model which explicitly considered both sites was proposed in the 1970s and the basic idea was widely accepted by later models. However, all these models did not systematically investigate the dominant factor on DNAP fidelity, i.e. the higher-order terminal effects through which the polymerization pathway and the proofreading pathway coordinate to achieve high fidelity. In this paper, we propose a new and comprehensive kinetic model of DNAP based on some recent experimental observations, which includes previous models as special cases. We present a rigorous and unified treatment of the corresponding steady-state kinetic equations of any-order terminal effects, and derive analytical expressions for fidelity in terms of kinetic parameters under bio-relevant conditions. These expressions offer new insights on how the higher-order terminal effects contribute substantially to the fidelity in an order-by-order way, and also show that the polymerization-and-proofreading mechanism is dominated only by very few key parameters. We then apply these results to calculate the fidelity of some real DNAPs, which are in good agreements with previous intuitive estimates given by experimentalists.
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Affiliation(s)
- Yong-Shun Song
- School of Physical Sciences, University of Chinese Academy of Sciences, No 19A Yuquan Road, Beijing 100049, People's Republic of China
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Raper AT, Reed AJ, Gadkari VV, Suo Z. Advances in Structural and Single-Molecule Methods for Investigating DNA Lesion Bypass and Repair Polymerases. Chem Res Toxicol 2016; 30:260-269. [PMID: 28092942 DOI: 10.1021/acs.chemrestox.6b00342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Innovative advances in X-ray crystallography and single-molecule biophysics have yielded unprecedented insight into the mechanisms of DNA lesion bypass and damage repair. Time-dependent X-ray crystallography has been successfully applied to view the bypass of 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxoG), a major oxidative DNA lesion, and the incorporation of the triphosphate form, 8-oxo-dGTP, catalyzed by human DNA polymerase β. Significant findings of these studies are highlighted here, and their contributions to the current mechanistic understanding of mutagenic translesion DNA synthesis (TLS) and base excision repair are discussed. In addition, single-molecule Förster resonance energy transfer (smFRET) techniques have recently been adapted to investigate nucleotide binding and incorporation opposite undamaged dG and 8-oxoG by Sulfolobus solfataricus DNA polymerase IV (Dpo4), a model Y-family DNA polymerase. The mechanistic response of Dpo4 to a DNA lesion and the complex smFRET technique are described here. In this perspective, we also describe how time-dependent X-ray crystallography and smFRET can be used to achieve the spatial and temporal resolutions necessary to answer some of the mechanistic questions that remain in the fields of TLS and DNA damage repair.
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Affiliation(s)
- Austin T Raper
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Andrew J Reed
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Varun V Gadkari
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
| | - Zucai Suo
- Department of Chemistry and Biochemistry and The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States
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Ren Z. Molecular events during translocation and proofreading extracted from 200 static structures of DNA polymerase. Nucleic Acids Res 2016; 44:7457-74. [PMID: 27325739 PMCID: PMC5009745 DOI: 10.1093/nar/gkw555] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/07/2016] [Indexed: 01/26/2023] Open
Abstract
DNA polymerases in family B are workhorses of DNA replication that carry out the bulk of the job at a high speed with high accuracy. A polymerase in this family relies on a built-in exonuclease for proofreading. It has not been observed at the atomic resolution how the polymerase advances one nucleotide space on the DNA template strand after a correct nucleotide is incorporated, that is, a process known as translocation. It is even more puzzling how translocation is avoided after the primer strand is excised by the exonuclease and returned back to the polymerase active site once an error occurs. The structural events along the bifurcate pathways of translocation and proofreading have been unwittingly captured by hundreds of structures in Protein Data Bank. This study analyzes all available structures of a representative member in family B and reveals the orchestrated event sequence during translocation and proofreading.
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Affiliation(s)
- Zhong Ren
- Department of Chemistry, The University of Illinois at Chicago, Chicago, IL 60607, USA Renz Research, Inc., Westmont, IL 60559, USA
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Wang J. Destruction-and-diffraction by X-ray free-electron laser. Protein Sci 2016; 25:1585-92. [PMID: 27262052 DOI: 10.1002/pro.2959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 05/31/2016] [Indexed: 01/06/2023]
Abstract
It is common knowledge that macromolecular crystals are damaged by the X-rays they are exposed to during conventional data collection. One of the claims made about the crystallographic data collection now being collected using X-ray free-electron lasers (XFEL) is that they are unaffected by radiation damage. XFEL data sets are assembled by merging data obtained from a very large number of crystals, each of which is exposed to a single femtosecond pulse of radiation, the duration of which is so short that diffraction occurs before the damage done to the crystal has time to become manifest, i.e. "diffraction-before-destruction." However, recent theoretical studies have shown that many of the elemental electronic processes that ultimately result in the destruction of such crystals occur during a single pulse. It is predicted that the amplitudes of atomic scattering factor could be reduced by as much as 75% within the first 5 femtoseconds of such pulses, and that different atoms will respond in different ways. Experimental evidence is provided here that these predictions are correct.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, Connecticut 06520, New Haven
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Stodola JL, Stith CM, Burgers PM. Proficient Replication of the Yeast Genome by a Viral DNA Polymerase. J Biol Chem 2016; 291:11698-705. [PMID: 27072134 DOI: 10.1074/jbc.m116.728741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 11/06/2022] Open
Abstract
DNA replication in eukaryotic cells requires minimally three B-family DNA polymerases: Pol α, Pol δ, and Pol ϵ. Pol δ replicates and matures Okazaki fragments on the lagging strand of the replication fork. Saccharomyces cerevisiae Pol δ is a three-subunit enzyme (Pol3-Pol31-Pol32). A small C-terminal domain of the catalytic subunit Pol3 carries both iron-sulfur cluster and zinc-binding motifs, which mediate interactions with Pol31, and processive replication with the replication clamp proliferating cell nuclear antigen (PCNA), respectively. We show that the entire N-terminal domain of Pol3, containing polymerase and proofreading activities, could be effectively replaced by those from bacteriophage RB69, and could carry out chromosomal DNA replication in yeast with remarkable high fidelity, provided that adaptive mutations in the replication clamp PCNA were introduced. This result is consistent with the model that all essential interactions for DNA replication in yeast are mediated through the small C-terminal domain of Pol3. The chimeric polymerase carries out processive replication with PCNA in vitro; however, in yeast, it requires an increased involvement of the mutagenic translesion DNA polymerase ζ during DNA replication.
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Affiliation(s)
- Joseph L Stodola
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Carrie M Stith
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Peter M Burgers
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
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Liu B, Xue Q, Tang Y, Cao J, Guengerich FP, Zhang H. Mechanisms of mutagenesis: DNA replication in the presence of DNA damage. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2016; 768:53-67. [PMID: 27234563 PMCID: PMC5237373 DOI: 10.1016/j.mrrev.2016.03.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 02/07/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
Abstract
Environmental mutagens cause DNA damage that disturbs replication and produces mutations, leading to cancer and other diseases. We discuss mechanisms of mutagenesis resulting from DNA damage, from the level of DNA replication by a single polymerase to the complex DNA replisome of some typical model organisms (including bacteriophage T7, T4, Sulfolobus solfataricus, Escherichia coli, yeast and human). For a single DNA polymerase, DNA damage can affect replication in three major ways: reducing replication fidelity, causing frameshift mutations, and blocking replication. For the DNA replisome, protein interactions and the functions of accessory proteins can yield rather different results even with a single DNA polymerase. The mechanism of mutation during replication performed by the DNA replisome is a long-standing question. Using new methods and techniques, the replisomes of certain organisms and human cell extracts can now be investigated with regard to the bypass of DNA damage. In this review, we consider the molecular mechanism of mutagenesis resulting from DNA damage in replication at the levels of single DNA polymerases and complex DNA replisomes, including translesion DNA synthesis.
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Affiliation(s)
- Binyan Liu
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - Qizhen Xue
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - Yong Tang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - Jia Cao
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - F Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Huidong Zhang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
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