1
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Maghsoud Y, Roy A, Leddin EM, Cisneros GA. Effects of the Y432S Cancer-Associated Variant on the Reaction Mechanism of Human DNA Polymerase κ. J Chem Inf Model 2024; 64:4231-4249. [PMID: 38717969 PMCID: PMC11181361 DOI: 10.1021/acs.jcim.4c00339] [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] [Indexed: 05/28/2024]
Abstract
Human DNA polymerases are vital for genetic information management. Their function involves catalyzing the synthesis of DNA strands with unparalleled accuracy, which ensures the fidelity and stability of the human genomic blueprint. Several disease-associated mutations and their functional impact on DNA polymerases have been reported. One particular polymerase, human DNA polymerase kappa (Pol κ), has been reported to be susceptible to several cancer-associated mutations. The Y432S mutation in Pol κ, associated with various cancers, is of interest due to its impact on polymerization activity and markedly reduced thermal stability. Here, we have used computational simulations to investigate the functional consequences of the Y432S using classical molecular dynamics (MD) and coupled quantum mechanics/molecular mechanics (QM/MM) methods. Our findings suggest that Y432S induces structural alterations in domains responsible for nucleotide addition and ternary complex stabilization while retaining structural features consistent with possible catalysis in the active site. Calculations of the minimum energy path associated with the reaction mechanism of the wild type (WT) and Y432S Pol κ indicate that, while both enzymes are catalytically competent (in terms of energetics and the active site's geometries), the cancer mutation results in an endoergic reaction and an increase in the catalytic barrier. Interactions with a third magnesium ion and environmental effects on nonbonded interactions, particularly involving key residues, contribute to the kinetic and thermodynamic distinctions between the WT and mutant during the catalytic reaction. The energetics and electronic findings suggest that active site residues favor the catalytic reaction with dCTP3- over dCTP4-.
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Affiliation(s)
- Yazdan Maghsoud
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Arkanil Roy
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Emmett M Leddin
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - G Andrés Cisneros
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, United States
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2
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Das CK, Gupta A, Nair NN. Probing the general base for DNA polymerization in telomerase: a molecular dynamics investigation. Phys Chem Chem Phys 2023; 25:14147-14157. [PMID: 37162325 DOI: 10.1039/d3cp00521f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Telomerase is an RNA-dependent DNA polymerase that plays a role in the maintenance of the 3' end of the eukaryotic chromosome, known as a telomere, by catalyzing the DNA polymerization reaction in cancer and embryonic stem cells. The detailed molecular details of the DNA polymerization by telomerase, especially the general base for deprotonating the terminal 3'-hydroxyl, which triggers the chemical reaction, remain elusive. We conducted a computational investigation using hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations to probe the detailed mechanism of the reaction. Our simulations started with the telomerase:RNA:DNA:dNTP ternary complex, and by using enhanced sampling QM/MM MD simulations, we probed the general base involved directly in the polymerization. We report the participation of an aspartate (Asp344) coordinated to Mg and an active site water molecule, jointly acting as a base during nucleic acid addition. The Asp344 residue remains transiently protonated during the course of the reaction, and later it deprotonates by transferring its proton to the water at the end of the reaction.
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Affiliation(s)
- Chandan Kumar Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Abhinav Gupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
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3
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Pan X, Van R, Epifanovsky E, Liu J, Pu J, Nam K, Shao Y. Accelerating Ab Initio Quantum Mechanical and Molecular Mechanical (QM/MM) Molecular Dynamics Simulations with Multiple Time Step Integration and a Recalibrated Semiempirical QM/MM Hamiltonian. J Phys Chem B 2022; 126:10.1021/acs.jpcb.2c02262. [PMID: 35653199 PMCID: PMC9715852 DOI: 10.1021/acs.jpcb.2c02262] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular dynamics (MD) simulations employing ab initio quantum mechanical and molecular mechanical (ai-QM/MM) potentials are considered to be the state of the art, but the high computational cost associated with the ai-QM calculations remains a theoretical challenge for their routine application. Here, we present a modified protocol of the multiple time step (MTS) method for accelerating ai-QM/MM MD simulations of condensed-phase reactions. Within a previous MTS protocol [Nam J. Chem. Theory Comput. 2014, 10, 4175], reference forces are evaluated using a low-level (semiempirical QM/MM) Hamiltonian and employed at inner time steps to propagate the nuclear motions. Correction forces, which arise from the force differences between high-level (ai-QM/MM) and low-level Hamiltonians, are applied at outer time steps, where the MTS algorithm allows the time-reversible integration of the correction forces. To increase the outer step size, which is bound by the highest-frequency component in the correction forces, the semiempirical QM Hamiltonian is recalibrated in this work to minimize the magnitude of the correction forces. The remaining high-frequency modes, which are mainly bond stretches involving hydrogen atoms, are then removed from the correction forces. When combined with a Langevin or SIN(R) thermostat, the modified MTS-QM/MM scheme remains robust with an up to 8 (with Langevin) or 10 fs (with SIN(R)) outer time step (with 1 fs inner time steps) for the chorismate mutase system. This leads to an over 5-fold speedup over standard ai-QM/MM simulations, without sacrificing the accuracy in the predicted free energy profile of the reaction.
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Affiliation(s)
- Xiaoliang Pan
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
| | - Richard Van
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
| | - Evgeny Epifanovsky
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, United States
| | - Jian Liu
- Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jingzhi Pu
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, 402 N Blackford St., LD326, Indianapolis, Indiana 46202, United States
| | - Kwangho Nam
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
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4
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Zhao J, Zheng X. Progress on Exploring the Luminescent Properties of Organic Molecular Aggregates by Multiscale Modeling. Front Chem 2022; 9:808957. [PMID: 35096770 PMCID: PMC8790572 DOI: 10.3389/fchem.2021.808957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/03/2021] [Indexed: 11/20/2022] Open
Abstract
Luminescent molecular aggregates have attracted worldwide attention because of their potential applications in many fields. The luminescent properties of organic aggregates are complicated and highly morphology-dependent, unraveling the intrinsic mechanism behind is urgent. This review summarizes recent works on investigating the structure-property relationships of organic molecular aggregates at different environments, including crystal, cocrystal, amorphous aggregate, and doped systems by multiscale modeling protocol. We aim to explore the influence of intermolecular non-covalent interactions on molecular packing and their photophysical properties and then pave the effective way to design, synthesize, and develop advanced organic luminescent materials.
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Affiliation(s)
- Jingyi Zhao
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science of Ministry of Education, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Xiaoyan Zheng
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science of Ministry of Education, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering, Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
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5
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Geronimo I, Vidossich P, Donati E, Vivo M. Computational investigations of polymerase enzymes: Structure, function, inhibition, and biotechnology. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Inacrist Geronimo
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia Genoa Italy
| | - Pietro Vidossich
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia Genoa Italy
| | - Elisa Donati
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia Genoa Italy
| | - Marco Vivo
- Laboratory of Molecular Modelling and Drug Discovery, Istituto Italiano di Tecnologia Genoa Italy
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6
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Ji S, Fu I, Naldiga S, Shao H, Basu AK, Broyde S, Tretyakova NY. 5-Formylcytosine mediated DNA-protein cross-links block DNA replication and induce mutations in human cells. Nucleic Acids Res 2019; 46:6455-6469. [PMID: 29905846 PMCID: PMC6061883 DOI: 10.1093/nar/gky444] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 05/29/2018] [Indexed: 12/24/2022] Open
Abstract
5-Formylcytosine (5fC) is an epigenetic DNA modification introduced via TET protein-mediated oxidation of 5-methyl-dC. We recently reported that 5fC form reversible DNA–protein conjugates (DPCs) with histone proteins in living cells (Ji et al. (2017) Angew. Chem. Int. Ed., 56:14130–14134). We now examined the effects of 5fC mediated DPCs on DNA replication. Synthetic DNA duplexes containing site-specific DPCs between 5fC and lysine-containing proteins and peptides were subjected to primer extension experiments in the presence of human translesion synthesis DNA polymerases η and κ. We found that DPCs containing histones H2A or H4 completely inhibited DNA replication, but the replication block was removed when the proteins were subjected to proteolytic digestion. Cross-links to 11-mer or 31-mer peptides were bypassed by both polymerases in an error-prone manner, inducing targeted C→T transitions and –1 deletions. Similar types of mutations were observed when plasmids containing 5fC-peptide cross-links were replicated in human embryonic kidney (HEK) 293T cells. Molecular simulations of the 11-mer peptide-dC cross-links bound to human polymerases η and κ revealed that the peptide fits well on the DNA major groove side, and the modified dC forms a stable mismatch with incoming dATP via wobble base pairing in the polymerase active site.
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Affiliation(s)
- Shaofei Ji
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Iwen Fu
- Department of Biology, New York University, New York, NY 10003, USA
| | - Spandana Naldiga
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA
| | - Hongzhao Shao
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ashis K Basu
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA
| | - Suse Broyde
- Department of Biology, New York University, New York, NY 10003, USA
| | - Natalia Y Tretyakova
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
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7
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Wilson KA, Fernandes PA, Ramos MJ, Wetmore SD. Exploring the Identity of the General Base for a DNA Polymerase Catalyzed Reaction Using QM/MM: The Case Study of Human Translesion Synthesis Polymerase η. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04889] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Katie A. Wilson
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4 Canada
| | - Pedro A. Fernandes
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Maria J. Ramos
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Stacey D. Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4 Canada
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8
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Two symmetric arginine residues play distinct roles in Thermus thermophilus Argonaute DNA guide strand-mediated DNA target cleavage. Proc Natl Acad Sci U S A 2018; 116:845-853. [PMID: 30591565 DOI: 10.1073/pnas.1817041116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacterium Thermus thermophilus Argonaute (Ago; TtAgo) is a prokaryotic Ago (pAgo) that acts as the host defense against the uptake and propagation of foreign DNA by catalyzing the DNA cleavage reaction. The TtAgo active site consists of a plugged-in glutamate finger with two arginine residues (R545 and R486) located symmetrically around it. An interesting challenge is to understand how they can collaboratively facilitate enzymatic catalysis. In Kluyveromyces polysporus Ago, a eukaryotic Ago, the evolutionarily symmetrical residues are arginine and histidine, both of which function to stabilize the plugged-in catalytic tetrad conformation. Surprisingly, our simulation results indicated that, in TtAgo, only R545 is involved in the cleavage reaction by serving as a critical structural anchor to stabilize the catalytic tetrad Asp-Glu-Asp-Asp that is completed by the insertion of the glutamate finger, whereas R486 is not involved in target cleavage. The TtAgo-mediated target DNA cleavage occurs in a substrate-assisted mechanism, in which the pro-Rp (Rp, a tetrahedral phosphorus center with "R-type" chirality) oxygen of scissile phosphate acts as a general base to activate the nucleophilic water. Our unexpected theoretical findings on distinct roles played by R545 and R486 in TtAgo catalysis have been validated by single-point site-mutagenesis experiments, wherein the target cleavage is abolished for all mutants of R545. In sharp contrast, the cleavage activity is maintained for all mutants of R486. Our work provides mechanistic insights on the catalytic specificity of Ago proteins and could facilitate the design of new gene-editing tools in the long term.
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9
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Affiliation(s)
- Vito Genna
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - Elisa Donati
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - Marco De Vivo
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
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10
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Li Y, Bao L, Zhang R, Tang X, Zhang Q, Wang W. Insights into the error bypass of 1-Nitropyrene DNA adduct by DNA polymerase ι: A QM/MM study. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.08.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Walker AR, Cisneros GA. Computational Simulations of DNA Polymerases: Detailed Insights on Structure/Function/Mechanism from Native Proteins to Cancer Variants. Chem Res Toxicol 2017; 30:1922-1935. [PMID: 28877429 PMCID: PMC5696005 DOI: 10.1021/acs.chemrestox.7b00161] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Genetic information is vital in the
cell cycle of DNA-based organisms.
DNA polymerases (DNA Pols) are crucial players in transactions dealing
with these processes. Therefore, the detailed understanding of the
structure, function, and mechanism of these proteins has been the
focus of significant effort. Computational simulations have been applied
to investigate various facets of DNA polymerase structure and function.
These simulations have provided significant insights over the years.
This perspective presents the results of various computational studies
that have been employed to research different aspects of DNA polymerases
including detailed reaction mechanism investigation, mutagenicity
of different metal cations, possible factors for fidelity synthesis,
and discovery/functional characterization of cancer-related mutations
on DNA polymerases.
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Affiliation(s)
- Alice R Walker
- Department of Chemistry, University of North Texas , 1155 Union Circle, Denton, Texas 76203, United States
| | - G Andrés Cisneros
- Department of Chemistry, University of North Texas , 1155 Union Circle, Denton, Texas 76203, United States
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12
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Wu WJ, Yang W, Tsai MD. How DNA polymerases catalyse replication and repair with contrasting fidelity. Nat Rev Chem 2017. [DOI: 10.1038/s41570-017-0068] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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13
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Wilson KA, Wetmore SD. Conformational Flexibility of the Benzyl-Guanine Adduct in a Bypass Polymerase Active Site Permits Replication: Insights from Molecular Dynamics Simulations. Chem Res Toxicol 2017; 30:2013-2022. [PMID: 28810119 DOI: 10.1021/acs.chemrestox.7b00179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Katie A. Wilson
- Department of Chemistry and
Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
| | - Stacey D. Wetmore
- Department of Chemistry and
Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
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14
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Yang W, Weng PJ, Gao Y. A new paradigm of DNA synthesis: three-metal-ion catalysis. Cell Biosci 2016; 6:51. [PMID: 27602203 PMCID: PMC5012070 DOI: 10.1186/s13578-016-0118-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 09/01/2016] [Indexed: 01/11/2023] Open
Abstract
Enzyme catalysis has been studied for over a century. How it actually occurs has not been visualized until recently. By combining in crystallo reaction and X-ray diffraction analysis of reaction intermediates, we have obtained unprecedented atomic details of the DNA synthesis process. Contrary to the established theory that enzyme-substrate complexes and transition states have identical atomic composition and catalysis occurs by the two-metal-ion mechanism, we have discovered that an additional divalent cation has to be captured en route to product formation. Unlike the canonical two metal ions, which are coordinated by DNA polymerases, this third metal ion is free of enzyme coordination. Its location between the α- and β-phosphates of dNTP suggests that the third metal ion may drive the phosphoryltransfer from the leaving group opposite to the 3'-OH nucleophile. Experimental data indicate that binding of the third metal ion may be the rate-limiting step in DNA synthesis and the free energy associated with the metal-ion binding can overcome the activation barrier to the DNA synthesis reaction.
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Affiliation(s)
- Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 USA
| | - Peter J Weng
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 USA
| | - Yang Gao
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 USA
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15
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Genna V, Vidossich P, Ippoliti E, Carloni P, De Vivo M. A Self-Activated Mechanism for Nucleic Acid Polymerization Catalyzed by DNA/RNA Polymerases. J Am Chem Soc 2016; 138:14592-14598. [PMID: 27530537 DOI: 10.1021/jacs.6b05475] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The enzymatic polymerization of DNA and RNA is the basis for genetic inheritance for all living organisms. It is catalyzed by the DNA/RNA polymerase (Pol) superfamily. Here, bioinformatics analysis reveals that the incoming nucleotide substrate always forms an H-bond between its 3'-OH and β-phosphate moieties upon formation of the Michaelis complex. This previously unrecognized H-bond implies a novel self-activated mechanism (SAM), which synergistically connects the in situ nucleophile formation with subsequent nucleotide addition and, importantly, nucleic acid translocation. Thus, SAM allows an elegant and efficient closed-loop sequence of chemical and physical steps for Pol catalysis. This is markedly different from previous mechanistic hypotheses. Our proposed mechanism is corroborated via ab initio QM/MM simulations on a specific Pol, the human DNA polymerase-η, an enzyme involved in repairing damaged DNA. The structural conservation of DNA and RNA Pols supports the possible extension of SAM to Pol enzymes from the three domains of life.
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Affiliation(s)
- Vito Genna
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia , Via Morego 30, 16163, Genoa, Italy.,IAS-5/INM-9 Computational Biomedicine and JARA-HPC, Forschungszentrum Jülich , Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
| | - Pietro Vidossich
- IAS-5/INM-9 Computational Biomedicine and JARA-HPC, Forschungszentrum Jülich , Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
| | - Emiliano Ippoliti
- IAS-5/INM-9 Computational Biomedicine and JARA-HPC, Forschungszentrum Jülich , Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
| | - Paolo Carloni
- IAS-5/INM-9 Computational Biomedicine and JARA-HPC, Forschungszentrum Jülich , Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
| | - Marco De Vivo
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia , Via Morego 30, 16163, Genoa, Italy.,IAS-5/INM-9 Computational Biomedicine and JARA-HPC, Forschungszentrum Jülich , Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
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16
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Grigorenko BL, Knyazeva MA, Nemukhin AV. Analysis of proton wires in the enzyme active site suggests a mechanism of c-di-GMP hydrolysis by the EAL domain phosphodiesterases. Proteins 2016; 84:1670-1680. [PMID: 27479508 DOI: 10.1002/prot.25108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/30/2016] [Accepted: 07/25/2016] [Indexed: 11/08/2022]
Abstract
We report for the first time a hydrolysis mechanism of the cyclic dimeric guanosine monophosphate (c-di-GMP) by the EAL domain phosphodiesterases as revealed by molecular simulations. A model system for the enzyme-substrate complex was prepared on the base of the crystal structure of the EAL domain from the BlrP1 protein complexed with c-di-GMP. The nucleophilic hydroxide generated from the bridging water molecule appeared in a favorable position for attack on the phosphorus atom of c-di-GMP. The most difficult task was to find a pathway for a proton transfer to the O3' atom of c-di-GMP to promote the O3'P bond cleavage. We show that the hydrogen bond network extended over the chain of water molecules in the enzyme active site and the Glu359 and Asp303 side chains provides the relevant proton wires. The suggested mechanism is consistent with the structural, mutagenesis, and kinetic experimental studies on the EAL domain phosphodiesterases. Proteins 2016; 84:1670-1680. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Bella L Grigorenko
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow, 119991, Russia.,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow, 119334, Russia
| | - Marina A Knyazeva
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow, 119991, Russia
| | - Alexander V Nemukhin
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow, 119991, Russia. .,N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin Street, Moscow, 119334, Russia.
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17
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Zhou Y, Wang S, Li Y, Zhang Y. Born-Oppenheimer Ab Initio QM/MM Molecular Dynamics Simulations of Enzyme Reactions. Methods Enzymol 2016; 577:105-18. [PMID: 27498636 PMCID: PMC4986621 DOI: 10.1016/bs.mie.2016.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There are two key requirements for reliably simulating enzyme reactions: one is a reasonably accurate potential energy surface to describe the bond-forming/breaking process as well as to adequately model the heterogeneous enzyme environment; the other is to perform extensive sampling since an enzyme system consists of at least thousands of atoms and its energy landscape is very complex. One attractive approach to meet both daunting tasks is Born-Oppenheimer ab initio QM/MM molecular dynamics (aiQM/MM-MD) simulation with umbrella sampling. In this chapter, we describe our recently developed pseudobond Q-Chem-Amber interface, which employs a combined electrostatic-mechanical embedding scheme with periodic boundary condition and the particle mesh Ewald method for long-range electrostatics interactions. In our implementation, Q-Chem and the sander module of Amber are combined at the source code level without using system calls, and all necessary data communications between QM and MM calculations are achieved via computer memory. We demonstrate the applicability of this pseudobond Q-Chem-Amber interface by presenting two examples, one reaction in aqueous solution and one enzyme reaction. Finally, we describe our established aiQM/MM-MD enzyme simulation protocol, which has been successfully applied to study more than a dozen enzymes.
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Affiliation(s)
- Y Zhou
- Laboratory of Mesoscopic Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
| | - S Wang
- New York University, New York, NY, United States
| | - Y Li
- International Center of Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, China
| | - Y Zhang
- New York University, New York, NY, United States; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, China.
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18
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Dans PD, Walther J, Gómez H, Orozco M. Multiscale simulation of DNA. Curr Opin Struct Biol 2016; 37:29-45. [DOI: 10.1016/j.sbi.2015.11.011] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 01/05/2023]
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19
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Jha V, Bian C, Xing G, Ling H. Structure and mechanism of error-free replication past the major benzo[a]pyrene adduct by human DNA polymerase κ. Nucleic Acids Res 2016; 44:4957-67. [PMID: 27034468 PMCID: PMC4889944 DOI: 10.1093/nar/gkw204] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 03/16/2016] [Indexed: 01/28/2023] Open
Abstract
Benzo[a]pyrene (BP) is a well-known and frequently encountered carcinogen which generates a bulky DNA adduct (+)-trans-10S-BP-N(2)-dG (BP-dG) in cells. DNA polymerase kappa (polκ) is the only known Y-family polymerase that bypasses BP-dG accurately and thus protects cells from genotoxic BP. Here, we report the structures of human polκ in complex with DNA containing either a normal guanine (G) base or a BP-dG adduct at the active site and a correct deoxycytidine. The structures and supporting biochemical data reveal a unique mechanism for accurate replication by translesion synthesis past the major bulky adduct. The active site of polκ opens at the minor groove side of the DNA substrate to accommodate the bulky BP-dG that is attached there. More importantly, polκ stabilizes the lesion DNA substrate in the same active conformation as for regular B-form DNA substrates and the bulky BPDE ring in a 5' end pointing conformation. The BP-dG adducted DNA substrate maintains a Watson-Crick (BP-dG:dC) base pair within the active site, governing correct nucleotide insertion opposite the bulky adduct. In addition, polκ's unique N-clasp domain supports the open conformation of the enzyme and the extended conformation of the single-stranded template to allow bypass of the bulky lesion. This work illustrates the first molecular mechanism for how a bulky major adduct is replicated accurately without strand misalignment and mis-insertion.
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Affiliation(s)
- Vikash Jha
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Chuanbing Bian
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Guangxin Xing
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Hong Ling
- Department of Biochemistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
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20
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Genna V, Gaspari R, Dal Peraro M, De Vivo M. Cooperative motion of a key positively charged residue and metal ions for DNA replication catalyzed by human DNA Polymerase-η. Nucleic Acids Res 2016; 44:2827-36. [PMID: 26935581 PMCID: PMC4824119 DOI: 10.1093/nar/gkw128] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/19/2016] [Indexed: 12/18/2022] Open
Abstract
Trans-lesion synthesis polymerases, like DNA Polymerase-η (Pol-η), are essential for cell survival. Pol-η bypasses ultraviolet-induced DNA damages via a two-metal-ion mechanism that assures DNA strand elongation, with formation of the leaving group pyrophosphate (PPi). Recent structural and kinetics studies have shown that Pol-η function depends on the highly flexible and conserved Arg61 and, intriguingly, on a transient third ion resolved at the catalytic site, as lately observed in other nucleic acid-processing metalloenzymes. How these conserved structural features facilitate DNA replication, however, is still poorly understood. Through extended molecular dynamics and free energy simulations, we unravel a highly cooperative and dynamic mechanism for DNA elongation and repair, which is here described by an equilibrium ensemble of structures that connect the reactants to the products in Pol-η catalysis. We reveal that specific conformations of Arg61 help facilitate the recruitment of the incoming base and favor the proper formation of a pre-reactive complex in Pol-η for efficient DNA editing. Also, we show that a third transient metal ion, which acts concertedly with Arg61, serves as an exit shuttle for the leaving PPi. Finally, we discuss how this effective and cooperative mechanism for DNA repair may be shared by other DNA-repairing polymerases.
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Affiliation(s)
- Vito Genna
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Roberto Gaspari
- CONCEPT Lab., Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland Swiss Institute of Bioinformatics (SIB), CH-1015, Lausanne, Switzerland
| | - Marco De Vivo
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy IAS-5 / INM-9 Computational Biomedicine Forschungszentrum Jülich, Wilhelm-Johnen-Straße 52428 Jülich, Germany
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21
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Toxicology of DNA Adducts Formed Upon Human Exposure to Carcinogens. ADVANCES IN MOLECULAR TOXICOLOGY 2016. [DOI: 10.1016/b978-0-12-804700-2.00007-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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22
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Zhang R, Bhattacharjee A, Field MJ, Salahub DR. Multiple proton relay routes in the reaction mechanism of RNAP II: Assessing the effect of structural model. Proteins 2014; 83:268-81. [DOI: 10.1002/prot.24732] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 11/05/2014] [Accepted: 11/06/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Rui Zhang
- Department of Chemistry; Centre for Molecular Simulation, Institute for Quantum Science and Technology, University of Calgary; Calgary Canada
| | - Anirban Bhattacharjee
- Department of Chemistry; Centre for Molecular Simulation, Institute for Quantum Science and Technology, University of Calgary; Calgary Canada
| | - Martin J. Field
- DYNAMOP; Institut de Biologie Structurale, Jean-Pierre Ebel; Grenoble France
| | - Dennis R. Salahub
- Department of Chemistry; Centre for Molecular Simulation, Institute for Quantum Science and Technology, University of Calgary; Calgary Canada
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23
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Perera L, Beard WA, Pedersen LG, Wilson SH. Applications of quantum mechanical/molecular mechanical methods to the chemical insertion step of DNA and RNA polymerization. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2014; 97:83-113. [PMID: 25458356 PMCID: PMC5573153 DOI: 10.1016/bs.apcsb.2014.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We review theoretical attempts to model the chemical insertion reactions of nucleoside triphosphates catalyzed by the nucleic acid polymerases using combined quantum mechanical/molecular mechanical methodology. Due to an existing excellent database of high-resolution X-ray crystal structures, the DNA polymerase β system serves as a useful template for discussion and comparison. The convergence of structures of high-quality complexes and continued developments of theoretical techniques suggest a bright future for understanding the global features of nucleic acid polymerization.
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Affiliation(s)
- Lalith Perera
- Laboratory of Structural Biology, National Institution of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
| | - William A Beard
- Laboratory of Structural Biology, National Institution of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Lee G Pedersen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Samuel H Wilson
- Laboratory of Structural Biology, National Institution of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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24
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Lior-Hoffmann L, Ding S, Geacintov NE, Zhang Y, Broyde S. Structural and dynamic characterization of polymerase κ's minor groove lesion processing reveals how adduct topology impacts fidelity. Biochemistry 2014; 53:5683-91. [PMID: 25148552 PMCID: PMC4159208 DOI: 10.1021/bi5007964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
DNA
lesion bypass polymerases process different lesions with varying
fidelities, but the structural, dynamic, and mechanistic origins of
this phenomenon remain poorly understood. Human DNA polymerase κ
(Polκ), a member of the Y family of lesion bypass polymerases,
is specialized to bypass bulky DNA minor groove lesions in a predominantly
error-free manner, by housing them in its unique gap. We have investigated
the role of the unique Polκ gap and N-clasp structural features
in the fidelity of minor groove lesion processing with extensive molecular
modeling and molecular dynamics simulations to pinpoint their functioning
in lesion bypass. Here we consider the N2-dG covalent adduct derived from the carcinogenic aromatic amine,
2-acetylaminofluorene (dG-N2-AAF), that
is produced via the combustion of kerosene and diesel fuel. Our simulations
reveal how the spacious gap directionally accommodates the lesion
aromatic ring system as it transits through the stages of incorporation
of the predominant correct partner dCTP opposite the damaged guanine,
with preservation of local active site organization for nucleotidyl
transfer. Furthermore, flexibility in Polκ’s N-clasp
facilitates the significant misincorporation of dTTP opposite dG-N2-AAF via wobble pairing. Notably, we show that
N-clasp flexibility depends on lesion topology, being markedly reduced
in the case of the benzo[a]pyrene-derived major adduct
to N2-dG, whose bypass by Polκ is
nearly error-free. Thus, our studies reveal how Polκ’s
unique structural and dynamic properties can regulate its bypass fidelity
of polycyclic aromatic lesions and how the fidelity is impacted by
lesion structures.
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Affiliation(s)
- Lee Lior-Hoffmann
- Department of Biology and ‡Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States
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25
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Yang W. An overview of Y-Family DNA polymerases and a case study of human DNA polymerase η. Biochemistry 2014; 53:2793-803. [PMID: 24716551 PMCID: PMC4018060 DOI: 10.1021/bi500019s] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
![]()
Y-Family
DNA polymerases specialize in translesion synthesis, bypassing
damaged bases that would otherwise block the normal progression of
replication forks. Y-Family polymerases have unique structural features
that allow them to bind damaged DNA and use a modified template base
to direct nucleotide incorporation. Each Y-Family polymerase is unique
and has different preferences for lesions to bypass and for dNTPs
to incorporate. Y-Family polymerases are also characterized by a low
catalytic efficiency, a low processivity, and a low fidelity on normal
DNA. Recruitment of these specialized polymerases to replication forks
is therefore regulated. The catalytic center of the Y-Family polymerases
is highly conserved and homologous to that of high-fidelity and high-processivity
DNA replicases. In this review, structural differences between Y-Family
and A- and B-Family polymerases are compared and correlated with their
functional differences. A time-resolved X-ray crystallographic study
of the DNA synthesis reaction catalyzed by the Y-Family DNA polymerase
human polymerase η revealed transient elements that led to the
nucleotidyl-transfer reaction.
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Affiliation(s)
- Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
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26
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Variants of mouse DNA polymerase κ reveal a mechanism of efficient and accurate translesion synthesis past a benzo[a]pyrene dG adduct. Proc Natl Acad Sci U S A 2014; 111:1789-94. [PMID: 24449898 DOI: 10.1073/pnas.1324168111] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA polymerase κ (Polκ) is the only known Y-family DNA polymerase that bypasses the 10S (+)-trans-anti-benzo[a]pyrene diol epoxide (BPDE)-N(2)-deoxyguanine adducts efficiently and accurately. The unique features of Polκ, a large structure gap between the catalytic core and little finger domain and a 90-residue addition at the N terminus known as the N-clasp, may give rise to its special translesion capability. We designed and constructed two mouse Polκ variants, which have reduced gap size on both sides [Polκ Gap Mutant (PGM) 1] or one side flanking the template base (PGM2). These Polκ variants are nearly as efficient as WT in normal DNA synthesis, albeit with reduced accuracy. However, PGM1 is strongly blocked by the 10S (+)-trans-anti-BPDE-N(2)-dG lesion. Steady-state kinetic measurements reveal a significant reduction in efficiency of dCTP incorporation opposite the lesion by PGM1 and a moderate reduction by PGM2. Consistently, Polκ-deficient cells stably complemented with PGM1 GFP-Polκ remained hypersensitive to BPDE treatment, and complementation with WT or PGM2 GFP-Polκ restored BPDE resistance. Furthermore, deletion of the first 51 residues of the N-clasp in mouse Polκ (mPolκ(52-516)) leads to reduced polymerization activity, and the mutant PGM2(52-516) but not PGM1(52-516) can partially compensate the N-terminal deletion and restore the catalytic activity on normal DNA. However, neither WT nor PGM2 mPolκ(52-516) retains BPDE bypass activity. We conclude that the structural gap physically accommodates the bulky aromatic adduct and the N-clasp is essential for the structural integrity and flexibility of Polκ during translesion synthesis.
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27
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Enhanced Sampling in Molecular Dynamics Using Metadynamics, Replica-Exchange, and Temperature-Acceleration. ENTROPY 2013. [DOI: 10.3390/e16010163] [Citation(s) in RCA: 291] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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28
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Bergonzo C, Galindo-Murillo R, Cheatham TE. Molecular modeling of nucleic acid structure: energy and sampling. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2013; 54:7.8.1-7.8.21. [PMID: 24510800 DOI: 10.1002/0471142700.nc0708s54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An overview of computer simulation techniques as applied to nucleic acid systems is presented. This unit discusses methods used to treat energy and to sample representative configurations. Emphasis is placed on molecular mechanics and empirical force fields.
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Affiliation(s)
- Christina Bergonzo
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
| | - Rodrigo Galindo-Murillo
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
| | - Thomas E Cheatham
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
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29
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Quantum mechanical modeling: a tool for the understanding of enzyme reactions. Biomolecules 2013; 3:662-702. [PMID: 24970187 PMCID: PMC4030948 DOI: 10.3390/biom3030662] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/17/2013] [Accepted: 09/19/2013] [Indexed: 01/16/2023] Open
Abstract
Most enzyme reactions involve formation and cleavage of covalent bonds, while electrostatic effects, as well as dynamics of the active site and surrounding protein regions, may also be crucial. Accordingly, special computational methods are needed to provide an adequate description, which combine quantum mechanics for the reactive region with molecular mechanics and molecular dynamics describing the environment and dynamic effects, respectively. In this review we intend to give an overview to non-specialists on various enzyme models as well as established computational methods and describe applications to some specific cases. For the treatment of various enzyme mechanisms, special approaches are often needed to obtain results, which adequately refer to experimental data. As a result of the spectacular progress in the last two decades, most enzyme reactions can be quite precisely treated by various computational methods.
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30
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Yang J, Lior-Hoffmann L, Wang S, Zhang Y, Broyde S. DNA cytosine methylation: structural and thermodynamic characterization of the epigenetic marking mechanism. Biochemistry 2013; 52:2828-38. [PMID: 23528166 DOI: 10.1021/bi400163k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA cytosine methyltransferases regulate the expression of the genome through the precise epigenetic marking of certain cytosines with a methyl group, and aberrant methylation is a hallmark of human diseases including cancer. Targeting these enzymes for drug design is currently a high priority. We have utilized ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations to investigate extensively the reaction mechanism of the representative DNA methyltransferase HhaI (M.HhaI) from prokaryotes, whose overall mechanism is shared with the mammalian enzymes. We obtain for the first time full free energy profiles for the complete reaction, together with reaction dynamics in atomistic detail. Our results show an energetically preferred mechanism in which nucleophilic attack of cytosine C5 on the S-adenosyl-L-methionine (AdoMet) methyl group is concerted with formation of the Michael adduct between a conserved Cys in the active site with cytosine C6. Spontaneous and reversible proton transfer between a conserved Glu in the active site and cytosine N3 at the transition state was observed in our simulations, revealing the chemical participation of this Glu residue in the catalytic mechanism. Subsequently, the β-elimination of the C5 proton utilizes as base an OH(-) derived from a conserved crystal water that is part of a proton wire water channel, and this syn β-elimination reaction is the rate-limiting step. Design of novel cytosine methylation inhibitors would be advanced by our structural and thermodynamic characterization of the reaction mechanism.
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Affiliation(s)
- Jin Yang
- Department of Chemistry, New York University, New York, NY 10003, USA
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31
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Shi Y, Zhou Y, Wang S, Zhang Y. Sirtuin Deacetylation Mechanism and Catalytic Role of the Dynamic Cofactor Binding Loop. J Phys Chem Lett 2013; 4:491-495. [PMID: 23585919 PMCID: PMC3621114 DOI: 10.1021/jz302015s] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Sirtuins constitute a novel family of protein deacetylases and play critical roles in epigenetics, cell death, and metabolism. In spite of numerous experimental studies, the key and most complicated stage of its NAD+-dependent catalytic mechanism remains to be elusive. Herein by employing Born-Oppenheimer ab initio QM/MM molecular dynamics simulations, a state-of-the-art computational approach to study enzyme reactions, we have characterized the complete deacetylation mechanism for a sirtuin enzyme, determined its multistep free-energy reaction profile, and elucidated essential catalytic roles of the conserved dynamic cofactor binding loop. These new detailed mechanistic insights would facilitate the design of novel mechanism-based sirtuin modulators.
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Affiliation(s)
- Yawei Shi
- Department of Chemistry, New York University, New York, New York 10003
| | - Yanzi Zhou
- Department of Chemistry, New York University, New York, New York 10003
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China
| | - Shenglong Wang
- Department of Chemistry, New York University, New York, New York 10003
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, New York 10003
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32
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Rooklin DW, Lu M, Zhang Y. Revelation of a catalytic calcium-binding site elucidates unusual metal dependence of a human apyrase. J Am Chem Soc 2012; 134:15595-603. [PMID: 22928549 PMCID: PMC3461190 DOI: 10.1021/ja307267y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human soluble calcium-activated nucleotidase 1 (hSCAN-1) represents a new family of apyrase enzymes that catalyze the hydrolysis of nucleotide di- and triphosphates, thereby modulating extracellular purinergic and pyrimidinergic signaling. Among well-characterized phosphoryl transfer enzymes, hSCAN-1 is unique not only in its unusual calcium-dependent activation, but also in its novel phosphate-binding motif. Its catalytic site does not utilize backbone amide groups to bind phosphate, as in the common P-loop, but contains a large cluster of acidic ionizable side chains. By employing a state-of-the-art computational approach, we have revealed a previously uncharacterized catalytic calcium-binding site in hSCAN-1, which elucidates the unusual calcium-dependence of its apyrase activity. In a high-order coordination shell, the newly identified calcium ion organizes the active site residues to mediate nucleotide binding, to orient the nucleophilic water, and to facilitate the phosphoryl transfer reaction. From ab initio QM/MM molecular dynamics simulations with umbrella sampling, we have characterized a reverse protonation catalytic mechanism for hSCAN-1 and determined its free energy reaction profile. Our results are consistent with available experimental studies and provide new detailed insight into the structure-function relationship of this novel calcium-activated phosphoryl transfer enzyme.
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Affiliation(s)
- David W. Rooklin
- Department of Chemistry, New York University, New York, NY 10003
| | - Min Lu
- Public Health Research Institute Center, Department of Microbiology and Molecular Genetics, UMDNJ – New Jersey Medical School, Newark, NJ 07103
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, NY 10003
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33
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Cheatham TE, Brooks BR, Kollman PA. Molecular modeling of nucleic acid structure: energy and sampling. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2001; Chapter 7:Unit-7.8. [PMID: 18428876 PMCID: PMC4029503 DOI: 10.1002/0471142700.nc0708s04] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
An overview of computer simulation techniques as applied to nucleic acid systems is presented. This unit expands an accompanying overview unit (UNIT 7.5) by discussing methods used to treat the energy and sample representative configurations. Emphasis is placed on molecular mechanics and empirical force fields.
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