1
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Kaur R, Aboelnga MM, Nikkel DJ, Wetmore SD. The metal dependence of single-metal mediated phosphodiester bond cleavage: a QM/MM study of a multifaceted human enzyme. Phys Chem Chem Phys 2022; 24:29130-29140. [PMID: 36444615 DOI: 10.1039/d2cp04338f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nucleases catalyze the cleavage of phosphodiester bonds in nucleic acids using a range of metal cofactors. Although it is well accepted that many nucleases rely on two metal ions, the one-metal mediated pathway is debated. Furthermore, one-metal mediated nucleases maintain activity in the presence of many different metals, but the underlying reasons for this broad metal specificity are unknown. The human apurinic/apyrimidinic endonuclease (APE1), which plays a key role in DNA repair, transcription regulation, and gene expression, is a prototypical example of a one-metal dependent nuclease. Although Mg2+ is the native metal cofactor, APE1 remains catalytically active in the presence of several metals, with the rate decreasing as Mg2+ > Mn2+ > Ni2+ > Zn2+, while Ca2+ completely abolished the activity. The present work uses quantum mechanics-molecular mechanics techniques to map APE1-facilitated phosphodiester bond hydrolysis in the presence of these metals. The structural differences in stationary points along the reaction pathway shed light on the interplay between several factors that allow APE1 to remain catalytically active for various metals, with the trend in the barrier heights correlating with the experimentally reported APE1 catalytic activity. In contrast, Ca2+ significantly changes the metal coordination and active site geometry, and thus completely inhibits catalysis. Our work thereby provides support for the controversial single-metal mediated phosphodiester bond cleavage and clarifies uncertainties regarding the role of the metal and metal identity in this important reaction. This information is key for future medicinal and biotechnological applications including disease diagnosis and treatment, and protein engineering.
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Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, T1K 3M4, Canada.
| | - Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, T1K 3M4, Canada.
| | - Dylan J Nikkel
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, T1K 3M4, Canada.
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, T1K 3M4, Canada.
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2
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Parise A, Ciardullo G, Prejanò M, Lande ADL, Marino T. On the Recognition of Natural Substrate CTP and Endogenous Inhibitor ddhCTP of SARS-CoV-2 RNA-Dependent RNA Polymerase: A Molecular Dynamics Study. J Chem Inf Model 2022; 62:4916-4927. [PMID: 36219674 DOI: 10.1021/acs.jcim.2c01002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The novel coronavirus SARS-CoV-2 is the causative agent of the COVID-19 outbreak that is affecting the entire planet. As the pandemic is still spreading worldwide, with multiple mutations of the virus, it is of interest and of help to employ computational methods for identifying potential inhibitors of the enzymes responsible for viral replication. Attractive antiviral nucleotide analogue RNA-dependent RNA polymerase (RdRp) chain terminator inhibitors are investigated with this purpose. This study, based on molecular dynamics (MD) simulations, addresses the important aspects of the incorporation of an endogenously synthesized nucleoside triphosphate, ddhCTP, in comparison with the natural nucleobase cytidine triphosphate (CTP) in RdRp. The ddhCTP species is the product of the viperin antiviral protein as part of the innate immune response. The absence of the ribose 3'-OH in ddhCTP could have important implications in its inhibitory mechanism of RdRp. We built an in silico model of the RNA strand embedded in RdRp using experimental methods, starting from the cryo-electron microscopy structure and exploiting the information obtained by spectrometry on the RNA sequence. We determined that the model was stable during the MD simulation time. The obtained results provide deeper insights into the incorporation of nucleoside triphosphates, whose molecular mechanism by the RdRp active site still remains elusive.
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Affiliation(s)
- Angela Parise
- Dipartimento di Chimica e Tecnologie Chimiche, Università Della Calabria, Via Pietro Bucci, 87036 Arcavacata di Rende, CS, Italy.,Université Paris-Saclay, CNRS, Institut de Chimie Physique UMR8000, Orsay 91405, France
| | - Giada Ciardullo
- Dipartimento di Chimica e Tecnologie Chimiche, Università Della Calabria, Via Pietro Bucci, 87036 Arcavacata di Rende, CS, Italy
| | - Mario Prejanò
- Dipartimento di Chimica e Tecnologie Chimiche, Università Della Calabria, Via Pietro Bucci, 87036 Arcavacata di Rende, CS, Italy
| | - Aurélien de la Lande
- Université Paris-Saclay, CNRS, Institut de Chimie Physique UMR8000, Orsay 91405, France
| | - Tiziana Marino
- Dipartimento di Chimica e Tecnologie Chimiche, Università Della Calabria, Via Pietro Bucci, 87036 Arcavacata di Rende, CS, Italy
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3
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Ardiles CS, Rodríguez CC. Theoretical study for determining the type of interactions between a GG block of an alginate chain with metals Cu2+, Mn2+, Ca2+ and Mg2+. ARAB J CHEM 2021. [DOI: 10.1016/j.arabjc.2021.103325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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4
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Hix MA, Leddin EM, Cisneros GA. Combining Evolutionary Conservation and Quantum Topological Analyses To Determine Quantum Mechanics Subsystems for Biomolecular Quantum Mechanics/Molecular Mechanics Simulations. J Chem Theory Comput 2021; 17:4524-4537. [PMID: 34087064 PMCID: PMC8477969 DOI: 10.1021/acs.jctc.1c00313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Selection of residues and other molecular fragments for inclusion in the quantum mechanics (QM) region for QM/molecular mechanics (MM) simulations is an important step for these calculations. Here, we present an approach that combines protein sequence/structure evolution and electron localization function (ELF) analyses. The combination of these two analyses allows the determination of whether a residue needs to be included in the QM subsystem or can be represented by the MM environment. We have applied this approach on two systems previously investigated by QM/MM simulations, 4-oxalocrotonate tautomerase (4OT) and ten-eleven translocation-2 (TET2), that provide examples where fragments may or may not need to be included in the QM subsystem. Subsequently, we present the use of this approach to determine the appropriate QM subsystem to calculate the minimum energy path (MEP) for the reaction catalyzed by human DNA polymerase λ (Polλ) with a third cation in the active site. Our results suggest that the combination of protein evolutionary and ELF analyses provides insights into residue/molecular fragment selection for QM/MM simulations.
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Affiliation(s)
- Mark A Hix
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - Emmett M Leddin
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - G Andrés Cisneros
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
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5
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Khrenova MG, Tsirelson VG. The N···H hydrogen bond strength in the transition state at the limiting step determines the reactivity of cephalosporins in the active site of L1 metallo-β-lactamase. MENDELEEV COMMUNICATIONS 2019. [DOI: 10.1016/j.mencom.2019.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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Vázquez-Montelongo EA, Vázquez-Cervantes JE, Cisneros GA. Polarizable ab initio QM/MM Study of the Reaction Mechanism of N- tert-Butyloxycarbonylation of Aniline in [EMIm][BF₄]. Molecules 2018; 23:E2830. [PMID: 30384470 PMCID: PMC6278528 DOI: 10.3390/molecules23112830] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 10/27/2018] [Accepted: 10/29/2018] [Indexed: 12/25/2022] Open
Abstract
N-t e r t-butoxycarbonylation of amines in solution (water, organic solvents, or ionic liquids) is a common reaction for the preparation of drug molecules. To understand the reaction mechanism and the role of the solvent, quantum mechanical/molecular mechanical simulations using a polarizable multipolar force field with long⁻range electrostatic corrections were used to optimize the minimum energy paths (MEPs) associated with various possible reaction mechanisms employing the nudged elastic band (NEB) and the quadratic string method (QSM). The calculated reaction energies and energy barriers were compared with the corresponding gas-phase and dichloromethane results. Complementary Electron Localization Function (ELF)/NCI analyses provide insights on the critical structures along the MEP. The calculated results suggest the most likely path involves a sequential mechanism with the rate⁻limiting step corresponding to the nucleophilic attack of the aniline, followed by proton transfer and the release of CO 2 without the direct involvement of imidazolium cations as catalysts.
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Affiliation(s)
| | | | - G Andrés Cisneros
- Department of Chemistry, University of North Texas, Denton, TX 76201, USA.
- The Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, TX 76201, USA.
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7
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Lohrman J, Vázquez-Montelongo EA, Pramanik S, Day VW, Hix MA, Bowman-James K, Cisneros GA. Characterizing Hydrogen-Bond Interactions in Pyrazinetetracarboxamide Complexes: Insights from Experimental and Quantum Topological Analyses. Inorg Chem 2018; 57:9775-9778. [DOI: 10.1021/acs.inorgchem.8b00627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessica Lohrman
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Erik A. Vázquez-Montelongo
- Department of Chemistry, University of North Texas, 1508 W Mulberry Street, Denton, Texas 76201, United States
| | - Subhamay Pramanik
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Mark A. Hix
- Department of Chemistry, University of North Texas, 1508 W Mulberry Street, Denton, Texas 76201, United States
| | - Kristin Bowman-James
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - G. Andrés Cisneros
- Department of Chemistry, University of North Texas, 1508 W Mulberry Street, Denton, Texas 76201, United States
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8
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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: 18] [Impact Index Per Article: 2.6] [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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9
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Klvaňa M, Bren U, Florián J. Uniform Free-Energy Profiles of the P-O Bond Formation and Cleavage Reactions Catalyzed by DNA Polymerases β and λ. J Phys Chem B 2016; 120:13017-13030. [PMID: 27992186 PMCID: PMC5217713 DOI: 10.1021/acs.jpcb.6b08581] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Human
X-family DNA polymerases β (Polβ) and λ
(Polλ) catalyze the nucleotidyl-transfer reaction in the base
excision repair pathway of the cellular DNA damage response. Using
empirical valence bond and free-energy perturbation simulations, we
explore the feasibility of various mechanisms for the deprotonation
of the 3′-OH group of the primer DNA strand, and the subsequent
formation and cleavage of P–O bonds in four Polβ, two
truncated Polλ (tPolλ), and two tPolλ Loop1 mutant
(tPolλΔL1) systems differing in the initial X-ray crystal
structure and nascent base pair. The average calculated activation
free energies of 14, 18, and 22 kcal mol–1 for Polβ,
tPolλ, and tPolλΔL1, respectively, reproduce the
trend in the observed catalytic rate constants. The most feasible
reaction pathway consists of two successive steps: specific base (SB)
proton transfer followed by rate-limiting concerted formation and
cleavage of the P–O bonds. We identify linear free-energy relationships
(LFERs) which show that the differences in the overall activation
and reaction free energies among the eight studied systems are determined
by the reaction free energy of the SB proton transfer. We discuss
the implications of the LFERs and suggest pKa of the 3′-OH group as a predictor of the catalytic
rate of X-family DNA polymerases.
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Affiliation(s)
- Martin Klvaňa
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor , Smetanova ulica 17, 2000 Maribor, Slovenia.,Department of Chemistry and Biochemistry, Loyola University Chicago , 1032 W. Sheridan Road, Chicago, Illinois 60660, United States
| | - Urban Bren
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor , Smetanova ulica 17, 2000 Maribor, Slovenia.,Laboratory for Molecular Modeling, National Institute of Chemistry , Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
| | - Jan Florián
- Department of Chemistry and Biochemistry, Loyola University Chicago , 1032 W. Sheridan Road, Chicago, Illinois 60660, United States
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10
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Kratz EG, Walker AR, Lagardère L, Lipparini F, Piquemal JP, Cisneros GA. LICHEM: A QM/MM program for simulations with multipolar and polarizable force fields. J Comput Chem 2016; 37:1019-29. [PMID: 26781073 PMCID: PMC4808410 DOI: 10.1002/jcc.24295] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/21/2015] [Accepted: 12/17/2015] [Indexed: 12/23/2022]
Abstract
We introduce an initial implementation of the LICHEM software package. LICHEM can interface with Gaussian, PSI4, NWChem, TINKER, and TINKER-HP to enable QM/MM calculations using multipolar/polarizable force fields. LICHEM extracts forces and energies from unmodified QM and MM software packages to perform geometry optimizations, single-point energy calculations, or Monte Carlo simulations. When the QM and MM regions are connected by covalent bonds, the pseudo-bond approach is employed to smoothly transition between the QM region and the polarizable force field. A series of water clusters and small peptides have been employed to test our initial implementation. The results obtained from these test systems show the capabilities of the new software and highlight the importance of including explicit polarization. © 2016 Wiley Periodicals, Inc.
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11
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Viciano I, González-Navarrete P, Andrés J, Martí S. Joint Use of Bonding Evolution Theory and QM/MM Hybrid Method for Understanding the Hydrogen Abstraction Mechanism via Cytochrome P450 Aromatase. J Chem Theory Comput 2015; 11:1470-80. [DOI: 10.1021/ct501030q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ignacio Viciano
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
| | | | - Juan Andrés
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
| | - Sergio Martí
- Departament
de Química
Física i Analítica, Universitat Jaume I, 12071, Castellón, Spain
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12
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Chaudret R, Contreras-Garcia J, Delcey M, Parisel O, Yang W, Piquemal JP. Revisiting H 2O Nucleation around Au + and Hg 2+: The Peculiar "Pseudo-Soft" Character of the Gold Cation. J Chem Theory Comput 2014; 10:1900-1909. [PMID: 24860276 PMCID: PMC4025583 DOI: 10.1021/ct4006135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Indexed: 01/01/2023]
Abstract
In this contribution, we propose a deeper understanding of the electronic effects affecting the nucleation of water around the Au+ and Hg2+ metal cations using quantum chemistry. To do so, and in order to go beyond usual energetical studies, we make extensive use of state of the art quantum interpretative techniques combining ELF/NCI/QTAIM/EDA computations to capture all ranges of interactions stabilizing the well characterized microhydrated structures. The Electron Localization Function (ELF) topological analysis reveals the peculiar role of the Au+ outer-shell core electrons (subvalence) that appear already spatially preorganized once the addition of the first water molecule occurs. Thus, despite the addition of other water molecules, the electronic structure of Au(H2O)+ appears frozen due to relativistic effects leading to a maximal acceptation of only two waters in gold's first hydration shell. As the values of the QTAIM (Quantum Theory of Atoms in Molecules) cations's charge is discussed, the Non Covalent Interactions (NCI) analysis showed that Au+ appears still able to interact through longer range van der Waals interaction with the third or fourth hydration shell water molecules. As these types of interaction are not characteristic of either a hard or soft metal cation, we introduced the concept of a "pseudo-soft" cation to define Au+ behavior. Then, extending the study, we performed the same computations replacing Au+ with Hg2+, an isoelectronic cation. If Hg2+ behaves like Au+ for small water clusters, a topological, geometrical, and energetical transition appears when the number of water molecules increases. Regarding the HSAB theory, this transition is characteristic of a shift of Hg2+ from a pseudosoft form to a soft ion and appears to be due to a competition between the relativistic and correlation effects. Indeed, if relativistic effects are predominant, then mercury will behave like gold and have a similar subvalence/geometry; otherwise when correlation effects are predominant, Hg2+ behaves like a soft cation.
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Affiliation(s)
- Robin Chaudret
- Sorbonne
Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- CNRS,
UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Julia Contreras-Garcia
- Sorbonne
Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- CNRS,
UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
| | - Mickaël Delcey
- Sorbonne
Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- CNRS,
UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- Department
of Chemistry − Uppsala University, Ångström Laboratory, Theoretical Chemistry, Ångströmlaboratoriet
Lägerhyddsvägen 1751 20 Uppsala, Sweden
| | - Olivier Parisel
- Sorbonne
Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- CNRS,
UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
| | - Weitao Yang
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Jean-Philip Piquemal
- Sorbonne
Universités, UPMC Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
- CNRS,
UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005, Paris, France
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13
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Rosta E, Yang W, Hummer G. Calcium inhibition of ribonuclease H1 two-metal ion catalysis. J Am Chem Soc 2014; 136:3137-44. [PMID: 24499076 PMCID: PMC3985467 DOI: 10.1021/ja411408x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Indexed: 01/05/2023]
Abstract
Most phosphate-processing enzymes require Mg(2+) as a cofactor to catalyze nucleotide cleavage and transfer reactions. Ca(2+) ions inhibit many of these enzymatic activities, despite Ca(2+) and Mg(2+) having comparable binding affinities and overall biological abundances. Here we study the molecular details of the calcium inhibition mechanism for phosphodiester cleavage, an essential reaction in the metabolism of nucleic acids and nucleotides, by comparing Ca(2+)- and Mg(2+) catalyzed reactions. We study the functional roles of the specific metal ion sites A and B in enabling the catalytic cleavage of an RNA/DNA hybrid substrate by B. halodurans ribonuclease (RNase) H1 using hybrid quantum-mechanics/molecular mechanics (QM/MM) free energy calculations. We find that Ca(2+) substitution of either of the two active-site Mg(2+) ions substantially increases the height of the reaction barrier and thereby abolishes the catalytic activity. Remarkably, Ca(2+) at the A site is inactive also in Mg(2+)-optimized active-site structures along the reaction path, whereas Mg(2+) substitution recovers activity in Ca(2+)-optimized structures. Geometric changes resulting from Ca(2+) substitution at metal ion site A may thus be a secondary factor in the loss of catalytic activity. By contrast, at metal ion site B geometry plays a more important role, with only a partial recovery of activity after Mg(2+) substitution in Ca(2+)-optimized structures. Ca(2+)-substitution also leads to a change in mechanism, with deprotonation of the water nucleophile requiring a closer approach to the scissile phosphate, which in turn increases the barrier. As a result, Ca(2+) is less efficient in activating the water. As a likely cause for the different reactivities of Mg(2+) and Ca(2+) ions in site A, we identify differences in charge transfer to the ions and the associated decrease in the pKa of the oxygen nucleophile attacking the phosphate group.
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Affiliation(s)
- Edina Rosta
- Laboratory
of Chemical Physics, National Institute of
Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
- Department
of Chemistry, King’s College London, London SE1 1DB, United Kingdom
| | - Wei Yang
- Laboratory
of Molecular Biology, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Gerhard Hummer
- Laboratory
of Chemical Physics, National Institute of
Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
- Department
of Theoretical Biophysics, Max Planck Institute
of Biophysics, 60438 Frankfurt am Main, Germany
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14
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Fang D, Chaudret R, Piquemal JP, Cisneros GA. Toward a Deeper Understanding of Enzyme Reactions Using the Coupled ELF/NCI Analysis: Application to DNA Repair Enzymes. J Chem Theory Comput 2013; 9:2156-60. [PMID: 26583709 DOI: 10.1021/ct400130b] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The combined Electron Localization Funtion (ELF)/ Noncovalent Interaction (NCI) topological analysis (Gillet et al. J. Chem. Theory Comput.2012, 8, 3993) has been extended to enzymatic reaction paths. We applied ELF/NCI to the reactions of DNA polymerase λ and the ε subunit of DNA polymerase III. ELF/NCI is shown to provide insights on the interactions during the evolution of enzymatic reactions including predicting the location of TS from structures located earlier along the reaction coordinate, differential metal coordination, and on barrier differences with two different cations.
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Affiliation(s)
- Dong Fang
- Department of Chemistry, Wayne State University, 5101 Cass Ave., Detroit, Michigan 48202, United States
| | - Robin Chaudret
- UPMC Univ Paris 06, UMR 7616 Laboratoire de Chimie Théorique, Case Courrier 137, 4 Place Jussieu, F-75005, Paris, France.,CNRS, UMR 7616, Laboratoire de Chimie Théorique, Case Courrier 137, 4 Place Jussieu, F-75005, Paris, France
| | - Jean-Philip Piquemal
- UPMC Univ Paris 06, UMR 7616 Laboratoire de Chimie Théorique, Case Courrier 137, 4 Place Jussieu, F-75005, Paris, France.,CNRS, UMR 7616, Laboratoire de Chimie Théorique, Case Courrier 137, 4 Place Jussieu, F-75005, Paris, France
| | - G Andrés Cisneros
- Department of Chemistry, Wayne State University, 5101 Cass Ave., Detroit, Michigan 48202, United States
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15
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The effect of intermolecular interactions on the electric dipole polarizabilities of nucleic acid base complexes. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.10.087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Sgrignani J, Magistrato A. The structural role of Mg2+ ions in a class I RNA polymerase ribozyme: a molecular simulation study. J Phys Chem B 2012; 116:2259-68. [PMID: 22268599 DOI: 10.1021/jp206475d] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
According to the RNA world hypothesis, self-replicating ribozymes, storing the genetic information and being able to perform catalysis, were the constituents of the first living organisms. In particular, RNA polymerase ribozymes, similar to current proteinaceous enzymatic polymerases, may have been able to promote the synthesis of RNA strands in a primitive world. Polymerase catalysis is usually assisted by Mg(2+) ions, but it is not always trivial to find out experimentally the number of Mg(2+) ions placed in the active site as well as the identity and the number of their coordination ligands. Here, we addressed this issue in an artificial class I ligase ribozyme. On the basis of a recently solved crystal structure, we constructed computational models of reactant and product states of this ribozyme, considering monometallic and bimetallic species. Our models were relaxed by force field based molecular dynamics (MD) simulations and mixed quantum-classical (QM/MM) MD. The structural and dynamical properties of these models were consistent with experimental data and were validated by a comparison with the catalytic sites of proteinaceous DNA and RNA polymerases. Consistently with enzymatic polymerases, our results suggest that class I RNA ligases most probably contain two magnesium ions in the active site and they may, therefore, catalyze the junction of two RNA strands via "a two Mg(2+) ions" mechanism.
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Affiliation(s)
- Jacopo Sgrignani
- CNR-IOM-Democritos National Simulation Center C/o International Studies for Advanced Studies (SISSA/ISAS), Via Bonomea 265, 34165, Trieste, Italy
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Klvaňa M, Jeřábek P, Goodman MF, Florián J. An abridged transition state model to derive structure, dynamics, and energy components of DNA polymerase β fidelity. Biochemistry 2011; 50:7023-32. [PMID: 21739967 DOI: 10.1021/bi200790s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We show how a restricted reaction surface can be used to facilitate the calculation of biologically important contributions of active site geometries and dynamics to DNA polymerase fidelity. Our analysis, using human DNA polymerase beta (pol β), is performed within the framework of an electrostatic linear free energy response (EFER) model. The structure, dynamics, and energetics of pol β-DNA-dNTP interactions are computed between two points on the multidimensional reaction free energy surface. "Point 1" represents a ground state activation intermediate (GSA), which is obtained by deprotonating the terminal 3'OH group of the primer DNA strand. "Point 2" is the transition state (PTS) for the attack of the 3'O(-) (O(nuc)) on the P(α) atom of dNTP substrate, having the electron density of a dianionic phosphorane intermediate. Classical molecular dynamics simulations are used to compute the geometric and dynamic contributions to the formation of right and wrong O(nuc)-P chemical bonds. Matched dCTP·G and mismatched dATP·G base pairs are used to illustrate the analysis. Compared to the dCTP·G base pair, the dATP·G mismatch has fewer GSA configurations with short distances between O(nuc) and P(α) atoms and between the oxygen in the scissile P-O bond (O(lg)) and the nearest structural water. The thumb subdomain conformation of the GSA complex is more open for the mismatch, and the H-bonds in the mispair become more extended during the nucleophilic attack than in the correct pair. The electrostatic contributions of pol β and DNA residues to catalysis of the right and wrong P-O(nuc) bond formation are 5.3 and 3.1 kcal/mol, respectively, resulting in an 80-fold contribution to fidelity. The EFER calculations illustrate the considerable importance of Arg183 and an O(lg)-proximal water molecule to pol β fidelity.
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Affiliation(s)
- Martin Klvaňa
- Department of Chemistry, Loyola University Chicago, Chicago, Illinois 60626, United States
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