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Pokorná P, Mlýnský V, Bussi G, Šponer J, Stadlbauer P. Molecular dynamics simulations reveal the parallel stranded d(GGGA) 3GGG DNA quadruplex folds via multiple paths from a coil-like ensemble. Int J Biol Macromol 2024; 261:129712. [PMID: 38286387 DOI: 10.1016/j.ijbiomac.2024.129712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/31/2024]
Abstract
G-quadruplexes (G4s) are non-canonical nucleic acid structures that fold through complex processes. Characterization of the G4 folding landscape may help to elucidate biological roles of G4s but is challenging both experimentally and computationally. Here, we achieved complete folding of a three-quartet parallel DNA G4 with (GGGA)3GGG sequence using all-atom explicit-solvent enhanced-sampling molecular dynamics (MD) simulations. The simulations suggested early formation of guanine stacks in the G-tracts, which behave as semi-rigid blocks in the folding process. The folding continues via the formation of a collapsed compact coil-like ensemble. Structuring of the G4 from the coil then proceeds via various cross-like, hairpin, slip-stranded and two-quartet ensembles and can bypass the G-triplex structure. Folding of the parallel G4 does not appear to involve any salient intermediates and is a multi-pathway process. We also carried out an extended set of simulations of parallel G-hairpins. While parallel G-hairpins are extremely unstable when isolated, they are more stable inside the coil structure. On the methodology side, we show that the AMBER DNA force field predicts the folded G4 to be less stable than the unfolded ensemble, uncovering substantial force-field issues. Overall, we provide unique atomistic insights into the folding landscape of parallel-stranded G4 but also reveal limitations of current state-of-the-art MD techniques.
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Affiliation(s)
- Pavlína Pokorná
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, Trieste 34136, Italy
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic.
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2
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Zalar M, Wang B, Plavec J, Šket P. Insight into Tetramolecular DNA G-Quadruplexes Associated with ALS and FTLD: Cation Interactions and Formation of Higher-Ordered Structure. Int J Mol Sci 2023; 24:13437. [PMID: 37686239 PMCID: PMC10487854 DOI: 10.3390/ijms241713437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The G4C2 hexanucleotide repeat expansion in the c9orf72 gene is a major genetic cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), with the formation of G-quadruplexes directly linked to the development of these diseases. Cations play a crucial role in the formation and structure of G-quadruplexes. In this study, we investigated the impact of biologically relevant potassium ions on G-quadruplex structures and utilized 15N-labeled ammonium cations as a substitute for K+ ions to gain further insights into cation binding and exchange dynamics. Through nuclear magnetic resonance spectroscopy and molecular dynamics simulations, we demonstrate that the single d(G4C2) repeat, in the presence of 15NH4+ ions, adopts a tetramolecular G-quadruplex with an all-syn quartet at the 5'-end. The movement of 15NH4+ ions through the central channel of the G-quadruplex, as well as to the bulk solution, is governed by the vacant cation binding site, in addition to the all-syn quartet at the 5'-end. Furthermore, the addition of K+ ions to G-quadruplexes folded in the presence of 15NH4+ ions induces stacking of G-quadruplexes via their 5'-end G-quartets, leading to the formation of stable higher-ordered species.
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Affiliation(s)
- Matja Zalar
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
| | - Baifan Wang
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
- EN-FIST Center of Excellence, Trg OF 13, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia; (M.Z.); (B.W.); (J.P.)
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Liu Y, Li J, Zhang Y, Wang Y, Chen J, Bian Y, Xia Y, Yang MH, Zheng K, Wang KB, Kong LY. Structure of the Major G-Quadruplex in the Human EGFR Oncogene Promoter Adopts a Unique Folding Topology with a Distinctive Snap-Back Loop. J Am Chem Soc 2023; 145:16228-16237. [PMID: 37460135 DOI: 10.1021/jacs.3c05214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
EGFR tyrosine kinase inhibitors have made remarkable success in targeted cancer therapy. However, therapeutic resistance inevitably occurred and EGFR-targeting therapy has been demonstrated to have limited efficacy or utility in glioblastoma, colorectal cancer, and hepatocellular carcinoma. Therefore, there is a high demand for the development of new targets to inhibit EGFR signaling. Herein, we found that the EGFR oncogene proximal promoter sequence forms a unique type of snap-back loop containing G-quadruplex (G4), which can be targeted by small molecules. For the first time, we determined the NMR solution structure of this snap-back EGFR-G4, a three-tetrad-core, parallel-stranded G4 with naturally occurring flanking residues at both the 5'-end and 3'-end. The snap-back loop located at the 3'-end region forms a stable capping structure through two stacked G-triads connected by multiple potential hydrogen bonds. Notably, the flanking residues are consistently absent in reported snap-back G4s, raising the question of whether such structures truly exist under in vivo conditions. The resolved EGFR-G4 structure has eliminated the doubt and showed distinct structural features that distinguish it from the previously reported snap-back G4s, which lack the flanking residues. Furthermore, we found that the snap-back EGFR-G4 structure is highly stable and can form on an elongated DNA template to inhibit DNA polymerase. The unprecedented high-resolution EGFR-G4 structure has thus contributed a promising molecular target for developing alternative EGFR signaling inhibitors in cancer therapeutics. Meanwhile, the two stacked triads may provide an attractive site for specific small-molecule targeting.
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Affiliation(s)
- Yushuang Liu
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Jinzhu Li
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yongqiang Zhang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yingying Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Juannan Chen
- School of Biomedical Sciences, Hunan University, Changsha, Hunan 410082, People's Republic of China
| | - Yuting Bian
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yuanzheng Xia
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Ming-Hua Yang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Kewei Zheng
- School of Biomedical Sciences, Hunan University, Changsha, Hunan 410082, People's Republic of China
| | - Kai-Bo Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Ling-Yi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
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Green AT, Pickard AJ, Li R, MacKerell AD, Bierbach U, Cho SS. Computational and Experimental Characterization of rDNA and rRNA G-Quadruplexes. J Phys Chem B 2022; 126:609-619. [PMID: 35026949 DOI: 10.1021/acs.jpcb.1c08340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA G-quadruplexes in human telomeres and gene promoters are being extensively studied for their role in controlling the growth of cancer cells. G-quadruplexes have been unambiguously shown to exist both in vitro and in vivo, including in the guanine (G)-rich DNA genes encoding pre-ribosomal RNA (pre-rRNA), which is transcribed in the cell's nucleolus. Recent studies strongly suggest that these DNA sequences ("rDNA"), and the transcribed rRNA, are a potential anticancer target through the inhibition of RNA polymerase I (Pol I) in ribosome biogenesis, but the structures of ribosomal G-quadruplexes at atomic resolution are unknown and very little biophysical characterization has been performed on them to date. In the present study, circular dichroism (CD) spectroscopy is used to show that two putative rDNA G-quadruplex sequences, NUC 19P and NUC 23P and their counterpart rRNAs, predominantly adopt parallel topologies, reminiscent of the analogous telomeric quadruplex structures. Based on this information, we modeled parallel topology atomistic structures of the putative ribosomal G-quadruplexes. We then validated and refined the modeled ribosomal G-quadruplex structures using all-atom molecular dynamics (MD) simulations with the CHARMM36 force field in the presence and absence of stabilizing K+. Motivated by preliminary MD simulations of the telomeric parallel G-quadruplex (TEL 24P) in which the K+ ion is expelled, we used updated CHARMM36 force field K+ parameters that were optimized, targeting the data from quantum mechanical calculations and the polarizable Drude model force field. In subsequent MD simulations with optimized CHARMM36 parameters, the K+ ions are predominantly in the G-quadruplex channel and the rDNA G-quadruplexes have more well-defined, predominantly parallel-topology structures as compared to rRNA. In addition, NUC 19P is more structured than NUC 23P, which contains extended loops. Results from this study set the structural foundation for understanding G-quadruplex functions and the design of novel chemotherapeutics against these nucleolar targets and can be readily extended to other DNA and RNA G-quadruplexes.
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Affiliation(s)
- Adam T Green
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Amanda J Pickard
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Rongzhong Li
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
| | - Ulrich Bierbach
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Samuel S Cho
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
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Asha H, Stadlbauer P, Martínez-Fernández L, Banáš P, Šponer J, Improta R, Esposito L. Early steps of oxidative damage in DNA quadruplexes are position-dependent: Quantum mechanical and molecular dynamics analysis of human telomeric sequence containing ionized guanine. Int J Biol Macromol 2022; 194:882-894. [PMID: 34838862 DOI: 10.1016/j.ijbiomac.2021.11.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022]
Abstract
Guanine radical cation (G•+) is a key intermediate in many oxidative processes occurring in nucleic acids. Here, by combining mixed Quantum Mechanical/Molecular Mechanics calculations and Molecular Dynamics (MD) simulations, we study how the structural behaviour of a tract GGG(TTAGGG)3 (hereafter Tel21) of the human telomeric sequence, folded in an antiparallel quadruple helix, changes when one of the G bases is ionized to G•+ (Tel21+). Once assessed that the electron-hole is localized on a single G, we perform MD simulations of twelve Tel21+ systems, differing in the position of G•+ in the sequence. When G•+ is located in the tetrad adjacent to the diagonal loop, we observe substantial structural rearrangements, which can decrease the electrostatic repulsion with the inner Na+ ions and increase the solvent exposed surface of G•+. Analysis of solvation patterns of G•+ provides new insights on the main reactions of G•+, i.e. the deprotonation at two different sites and hydration at the C8 atom, the first steps of the processes producing 8oxo-Guanine. We suggest the main structural determinants of the relative reactivity of each position and our conclusions, consistent with the available experimental trends, can help rationalizing the reactivity of other G-quadruplex topologies.
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Affiliation(s)
- Haritha Asha
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Lara Martínez-Fernández
- Departamento de Quimica, Facultad de Ciencias and Institute for Advanced Research in Chemistry (IADCHEM), Universidad Autonoma de Madrid, Campus de Excelencia UAM-CSIC, 28049 Madrid, Spain
| | - Pavel Banáš
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University, Křížkovského 8, 779 00 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.
| | - Roberto Improta
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy.
| | - Luciana Esposito
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy.
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6
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Liu YC, Yang DY, Sheu SY. Insights into the free energy landscape and salt-controlled mechanism of the conformational conversions between human telomeric G-quadruplex structures. Int J Biol Macromol 2021; 191:230-242. [PMID: 34536474 DOI: 10.1016/j.ijbiomac.2021.09.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/23/2021] [Accepted: 09/10/2021] [Indexed: 12/16/2022]
Abstract
G-quadruplexes have become attractive drug targets in cancer therapy. However, due to the polymorphism of G-quadruplex structures, it is difficult to experimentally verify the relevant structures of multiple intermediates and transition states in dynamic equilibrium. Hence, understanding the mechanism by which structural conversions of G-quadruplexes occur is still challenging. We conducted targeted molecular dynamics simulation with umbrella sampling to investigate how salt affects the conformational conversion of human telomeric G-quadruplex. Our results explore a unique view into the structures and energy barrier of the intermediates and transition states in the interconversion process. The pathway of G-quadruplex conformational interconversion was mapped out by a free energy landscape, consisting of branched parallel pathways with multiple energy basins. We propose a salt-controlled mechanism that as the salt concentration increases, the conformational conversion mechanism switches from multi-pathway folding to sequential folding pathways. The hybrid-I and hybrid-II structures are intermediates in the basket-propeller transformation. In high-salt solutions, the conformational conversion upon K+ binding is more feasible than upon Na+ binding. The free energy barrier for conformational conversions ranges from 1.6 to 4.6 kcal/mol. Our work will be beneficial in developing anticancer agents.
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Affiliation(s)
- Yu-Cheng Liu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Dah-Yen Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
| | - Sheh-Yi Sheu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
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7
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Sánchez-González Á, Bandeira NAG, Ortiz de Luzuriaga I, Martins FF, Elleuchi S, Jarraya K, Lanuza J, Lopez X, Calhorda MJ, Gil A. New Insights on the Interaction of Phenanthroline Based Ligands and Metal Complexes and Polyoxometalates with Duplex DNA and G-Quadruplexes. Molecules 2021; 26:4737. [PMID: 34443326 PMCID: PMC8397986 DOI: 10.3390/molecules26164737] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/24/2022] Open
Abstract
This work provides new insights from our team regarding advances in targeting canonical and non-canonical nucleic acid structures. This modality of medical treatment is used as a form of molecular medicine specifically against the growth of cancer cells. Nevertheless, because of increasing concerns about bacterial antibiotic resistance, this medical strategy is also being explored in this field. Up to three strategies for the use of DNA as target have been studied in our research lines during the last few years: (1) the intercalation of phenanthroline derivatives with duplex DNA; (2) the interaction of metal complexes containing phenanthroline with G-quadruplexes; and (3) the activity of Mo polyoxometalates and other Mo-oxo species as artificial phosphoesterases to catalyze the hydrolysis of phosphoester bonds in DNA. We demonstrate some promising computational results concerning the favorable interaction of these small molecules with DNA that could correspond to cytotoxic effects against tumoral cells and microorganisms. Therefore, our results open the door for the pharmaceutical and medical applications of the compounds we propose.
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Affiliation(s)
- Ángel Sánchez-González
- Faculdade de Ciências, BioISI-Biosystems and Integrative Sciences Institute, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (Á.S.-G.); (N.A.G.B.); (F.F.M.); (M.J.C.)
| | - Nuno A. G. Bandeira
- Faculdade de Ciências, BioISI-Biosystems and Integrative Sciences Institute, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (Á.S.-G.); (N.A.G.B.); (F.F.M.); (M.J.C.)
| | - Iker Ortiz de Luzuriaga
- CIC nanoGUNE BRTA, Tolosa Hiribidea 76, Euskadi, 20018 Donostia-San Sebastián, Spain;
- Polimero eta Material Aurreratuak, Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel de Lardizabal 3, 20018 Donostia-San Sebastián, Spain; (J.L.); (X.L.)
| | - Frederico F. Martins
- Faculdade de Ciências, BioISI-Biosystems and Integrative Sciences Institute, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (Á.S.-G.); (N.A.G.B.); (F.F.M.); (M.J.C.)
| | - Sawssen Elleuchi
- Laboratoire de Chimie Inorganique, LR17ES07, Faculté de Sciences de Sfax, Université de Sfax, Sfax 3000, Tunisia; (S.E.); (K.J.)
| | - Khaled Jarraya
- Laboratoire de Chimie Inorganique, LR17ES07, Faculté de Sciences de Sfax, Université de Sfax, Sfax 3000, Tunisia; (S.E.); (K.J.)
| | - Jose Lanuza
- Polimero eta Material Aurreratuak, Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel de Lardizabal 3, 20018 Donostia-San Sebastián, Spain; (J.L.); (X.L.)
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain
| | - Xabier Lopez
- Polimero eta Material Aurreratuak, Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel de Lardizabal 3, 20018 Donostia-San Sebastián, Spain; (J.L.); (X.L.)
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain
| | - Maria José Calhorda
- Faculdade de Ciências, BioISI-Biosystems and Integrative Sciences Institute, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (Á.S.-G.); (N.A.G.B.); (F.F.M.); (M.J.C.)
| | - Adrià Gil
- Faculdade de Ciências, BioISI-Biosystems and Integrative Sciences Institute, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (Á.S.-G.); (N.A.G.B.); (F.F.M.); (M.J.C.)
- CIC nanoGUNE BRTA, Tolosa Hiribidea 76, Euskadi, 20018 Donostia-San Sebastián, Spain;
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Sheng Y, Cao B, Ou M, Wang Y, Yuan S, Zhang N, Zou T, Liu Y. Nucleocapsid protein preferentially binds the stem-loop of duplex/quadruplex hybrid that unfolds the quadruplex structure. Chem Commun (Camb) 2021; 57:5298-5301. [PMID: 33942834 DOI: 10.1039/d1cc01767e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
NCp7 protein binds the duplex/quadruplex hybrid structure, which decreases the thermal stability of DNA and unfolds the G-quadruplex structure. Interestingly, the duplex in the stem-loop region is the more favorable binding site of NCp7. The NCp7 binding twists the top G-tetrad, weakens hydrogen bonding and causes K+ ejection, hence disrupting the G4 structure.
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Affiliation(s)
- Yaping Sheng
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Bei Cao
- Warshel Institute for Computational Biology and General Education Division, The Chinese University of Hong Kong, Shenzhen, 518172, P. R. China
| | - Mingxi Ou
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Yu Wang
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Siming Yuan
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Na Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Taotao Zou
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, P. R. China.
| | - Yangzhong Liu
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
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Dantu SC, Sicoli G. The 'hidden side' of spin labelled oligonucleotides: Molecular dynamics study focusing on the EPR-silent components of base pairing. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 324:106924. [PMID: 33581372 DOI: 10.1016/j.jmr.2021.106924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 12/31/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Nitroxide labels are combined with nucleic acid structures and are studied using electron paramagnetic resonance experiments (EPR). As X-ray/NMR structures are unavailable with the nitroxide labels, detailed residue level information, down to atomic resolution, about the effect of these nitroxide labels on local RNA structures is currently lacking. This information is critical to evaluate the choice of spin label. In this study, we compare and contrast the effect of TEMPO-based (NT) and rigid spin (Ç) labels (in both 2'-O methylated and not-methylated forms) on RNA duplexes. We also investigate sequence- dependent effects of NT label on RNA duplex along with the more complex G-quadruplex RNA. Distances measured from molecular dynamics simulations between the two spin labels are in agreement with the EPR experimental data. To understand the effect of labelled oligonucleotides on the structure, we studied the local base pair geometries and global structure in comparison with the unlabelled structures. Based on the structural analysis, we can conclude that TEMPO-based and Ç labels do not significantly perturb the base pair arrangements of the native oligonucleotide. When experimental structures for the spin labelled DNA/RNA molecules are not available, general framework offered by the current study can be used to provide information critical to the choice of spin labels to facilitate future EPR studies.
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Affiliation(s)
- Sarath Chandra Dantu
- Theoretical & Computational Biophysics Department, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany.
| | - Giuseppe Sicoli
- Laboratoire Avancé de Spectroscopie pour les Interactions, la Réactivité et l'Environnement (LASIRE), CNRS Lille, UMR 8516, Bâtiment C4 - Université de Lille, Sciences et Technologies, Avenue Paul Langevin 59655 Villeneuve-d'Ascq Cedex, France.
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Ortiz de Luzuriaga I, Lopez X, Gil A. Learning to Model G-Quadruplexes: Current Methods and Perspectives. Annu Rev Biophys 2021; 50:209-243. [PMID: 33561349 DOI: 10.1146/annurev-biophys-060320-091827] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G-quadruplexes have raised considerable interest during the past years for the development of therapies against cancer. These noncanonical structures of DNA may be found in telomeres and/or oncogene promoters, and it has been observed that the stabilization of such G-quadruplexes may disturb tumor cell growth. Nevertheless, the mechanisms leading to folding and stabilization of these G-quadruplexes are still not well established, and they are the focus of much current work in this field. In seminal works, stabilization was observed to be produced by cations. However, subsequent studies showed that different kinds of small molecules, from planar and nonplanar organic molecules to square-planar and octahedral metal complexes, may also lead to the stabilization of G-quadruplexes. Thus, the comprehension and rationalization of the interaction of these small molecules with G-quadruplexes are also important topics of current interest in medical applications. To shed light on the questions arising from the literature on the formation of G-quadruplexes, their stabilization, and their interaction with small molecules, synergies between experimental studies and computational works are needed. In this review, we mainly focus on in silico approaches and provide a broad compilation of different leading studies carried out to date by different computational methods. We divide these methods into twomain categories: (a) classical methods, which allow for long-timescale molecular dynamics simulations and the corresponding analysis of dynamical information, and (b) quantum methods (semiempirical, quantum mechanics/molecular mechanics, and density functional theory methods), which allow for the explicit simulation of the electronic structure of the system but, in general, are not capable of being used in long-timescale molecular dynamics simulations and, therefore, give a more static picture of the relevant processes.
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Affiliation(s)
- Iker Ortiz de Luzuriaga
- CIC nanoGUNE BRTA, 20018 Donostia, Euskadi, Spain; .,Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia, Kimika Fakultatea, Euskal Herriko Uniberstitatea, UPV/EHU, 20080 Donostia, Euskadi, Spain
| | - Xabier Lopez
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia, Kimika Fakultatea, Euskal Herriko Uniberstitatea, UPV/EHU, 20080 Donostia, Euskadi, Spain.,Donostia International Physics Center, 20018 Donostia, Spain
| | - Adrià Gil
- CIC nanoGUNE BRTA, 20018 Donostia, Euskadi, Spain; .,BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal;
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11
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Salsbury AM, Dean TJ, Lemkul JA. Polarizable Molecular Dynamics Simulations of Two c-kit Oncogene Promoter G-Quadruplexes: Effect of Primary and Secondary Structure on Loop and Ion Sampling. J Chem Theory Comput 2020; 16:3430-3444. [PMID: 32307997 DOI: 10.1021/acs.jctc.0c00191] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G-quadruplexes (GQs) are highly ordered nucleic acid structures that play fundamental roles in regulating gene expression and maintaining genomic stability. GQs are topologically diverse and enriched in promoter sequences of growth regulatory genes and proto-oncogenes, suggesting that they may serve as attractive targets for drug design at the level of transcription rather than inhibiting the activity of the protein products of these genes. The c-kit promoter contains three adjacent GQ-forming sequences that have proposed antagonistic effects on gene expression and thus are promising drug targets for diseases such as gastrointestinal stromal tumors, mast cell disease, and leukemia. Because GQ stability is influenced by primary structure, secondary structure, and ion interactions, a greater understanding of GQ structure, dynamics, and ion binding properties is needed to develop novel, GQ-targeting therapeutics. Here, we performed molecular dynamics simulations to systematically study the c-kit2 and c-kit* GQs, evaluating nonpolarizable and polarizable force fields (FFs) and examining the effects of base substitutions and cation type (K+, Na+, and Li+) on the dynamics of their isolated and linked structures. We found that the Drude polarizable FF outperformed the additive CHARMM36 FF in two- and three-tetrad GQs and solutions of KCl, NaCl, and LiCl. Drude simulations with different cations agreed with the known GQ stabilization preference (K+ > Na+ > Li+) and illustrated that tetrad core-ion coordination differs as a function of cation type. Finally, we showed that differences in primary and secondary structure influence loop sampling, ion binding, and core-ion energetics of GQs.
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Affiliation(s)
- Alexa M Salsbury
- Department of Biochemistry and Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Tanner J Dean
- Department of Biochemistry and Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Justin A Lemkul
- Department of Biochemistry and Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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12
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Molecular dynamics simulations of G-quadruplexes: The basic principles and their application to folding and ligand binding. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2020. [DOI: 10.1016/bs.armc.2020.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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13
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Martínez-Fernández L, Esposito L, Improta R. Studying the excited electronic states of guanine rich DNA quadruplexes by quantum mechanical methods: main achievements and perspectives. Photochem Photobiol Sci 2020; 19:436-444. [DOI: 10.1039/d0pp00065e] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calculations are providing more and more useful insights into the interaction between light and DNA quadruplexes.
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Affiliation(s)
- Lara Martínez-Fernández
- Departamento de Química
- Facultad de Ciencias
- Modulo 13 Universidad Autónoma de Madrid
- Campus de Excelencia UAM-CSIC Cantoblanco
- 28049 Madrid
| | | | - Roberto Improta
- Istituto di Biostrutture e Bioimmagini
- CNR
- I-80134 Napoli
- Italy
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14
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Portella G, Orozco M, Vendruscolo M. Determination of a Structural Ensemble Representing the Dynamics of a G-Quadruplex DNA. Biochemistry 2019; 59:379-388. [PMID: 31815441 DOI: 10.1021/acs.biochem.9b00493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is increasingly recognized that the structures and dynamics of G-quadruplex DNA molecules are dictated by their sequences and greatly affected by environmental factors. The core guanine tetrads (G-tetrads) coordinate cations and display a strong conformational rigidity compared with that of the connecting loops. Although long loops linking the G-tetrads are typically disfavored, when present, they provide a striking illustration of the dynamics of short, single-stranded DNA regions. In addition to their role in determining the stability of the G-quadruplex state, these loops are also interesting as potential drug targets. To characterize accurately the dynamics of this DNA state, we apply here the principles of structural ensemble determination developed in the past two decades for protein molecules to DNA molecules. We thus perform extensive molecular dynamics simulations restrained with nuclear magnetic resonance residual dipolar couplings to determine a structural ensemble of the human CEB25 minisatellite G-quadruplex, which contains a connecting loop of nine nucleotides. This structural ensemble displays a wide set of arrangements for the loop and a compact, well-defined G-quadruplex core. Our results show the importance of stacking interactions in the loop and strengthen the ability of the closing base pairs to confer a large thermodynamic stability to the G-quadruplex structure.
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Affiliation(s)
- Guillem Portella
- Department of Chemistry , University of Cambridge , Cambridge CB2 1EW , U.K.,Institute for Research in Biomedicine (IRB Barcelona) , Barcelona Institute for Science and Technology (BIST) , 08028 Barcelona , Spain.,Joint BSC-CRG-IRB Research Program in Computational Biology , 08028 Barcelona , Spain
| | - Modesto Orozco
- Institute for Research in Biomedicine (IRB Barcelona) , Barcelona Institute for Science and Technology (BIST) , 08028 Barcelona , Spain.,Joint BSC-CRG-IRB Research Program in Computational Biology , 08028 Barcelona , Spain.,Department of Biochemistry and Biomedicine , University of Barcelona , 08028 Barcelona , Spain
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15
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Why do G-quadruplexes dimerize through the 5'-ends? Driving forces for G4 DNA dimerization examined in atomic detail. PLoS Comput Biol 2019; 15:e1007383. [PMID: 31539370 PMCID: PMC6774569 DOI: 10.1371/journal.pcbi.1007383] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 10/02/2019] [Accepted: 09/09/2019] [Indexed: 12/25/2022] Open
Abstract
G-quadruplexes (G4) are secondary structures formed by guanine-rich nucleic acid sequences and shown to exist in living cells where they participate in regulation of gene expression and chromosome maintenance. G-quadruplexes with solvent-exposed guanine tetrads show the tendency to associate together through cofacial stacking, which may be important for packaging of G4-forming sequences and allows for the design of higher-order G4 DNA structures. To understand the molecular driving forces for G4 association, here, we study the binding interaction between two parallel-stranded G-quadruplexes using all-atom molecular dynamics simulations. The predicted dimerization free energies show that direct binding through the 5’-G-tetrads is the most preferred of all possible end-to-end stacking orientations, consistently with all available experimental data. Decomposition of dimerization enthalpies in combination with simulations at varying ionic strength further indicate that the observed orientational preferences arise from a fine balance between the electrostatic repulsion of the sugar-phosphate backbones and favorable counterion binding at the dimeric interface. We also demonstrate how these molecular-scale findings can be used to devise means of controlling G4 dimerization equilibrium, e.g., by altering salt concentration and using G4-targeted ligands. Native DNA usually folds to form the canonical double helix, however, under certain conditions, it can also fold into other secondary structures. Some of the most interesting ones are G-quadruplexes (G4)—compact DNA structures in which guanines assemble into multilayered tetrads, and whose formation has been reported at the ends of linear chromosomes (telomeres) and at different regulatory regions of the genome. Although structural and basic energetic properties, as well as some biological functions of G-quadruplexes are quite well understood, not much is known about their propensity to form agregated structures. A very high density of G-quadruplexes at telomeres along with their large exposed planar surfaces indeed favor G4 aggregation through end-to-end stacking, which might be important for the protection of telomeres and DNA packaging. In this research, using computer simulations, we provide insight into molecular origins of stability of the higher-order G-quadruplexes and explain in structural and energetic terms a strong preference for one particular end-to-end stacking orientation. Based on the recognized aggregation driving forces, we also suggest methods for controling the aggregation preferences openining up new opportunities for designing oligomeric G-quadruplexes.
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16
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Kim HW, Rhee YM, Shin SK. Charge-dipole interactions in G-quadruplex thrombin-binding aptamer. Phys Chem Chem Phys 2019; 20:21068-21074. [PMID: 30074033 DOI: 10.1039/c8cp03050b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
DNAs form various structures through hydrogen-bonding, base-stacking and electrostatic interactions. Although these noncovalent interactions are known to be cooperative in stabilizing a G-quadruplex (G4) structure of DNA, we find from all-atom molecular dynamics simulations that the electrostatic charge-dipole interaction is competitive with both hydrogen-bonding and base-stacking interactions. For the thrombin-binding aptamer (TBA) forming a chair-type antiparallel G4 structure, we have examined effects of an intercalating metal ion [K+, Sr2+, Mn+: an ion having a charge of n+ (n = 1-4) with the ionic radius of K+] on structural properties and noncovalent interactions. When K+ in the TBA·K+ complex is replaced with Sr2+, guanine dipoles in the two G-tetrads are realigned toward the central metal ion, thereby distorting the planar G4 geometry. Replacing K+ with Sr2+ significantly enhances the charge-dipole interaction but substantially reduces the number of hydrogen bonds in the G-tetrads. In the case of TBA·Mn+ complexes, as the charge n increases, the charge-dipole interaction increases but both of the hydrogen-bonding and base-stacking interactions decrease. These results suggest that the charge-dipole interaction realigning guanine dipoles in the G-tetrads is not cooperative but competitive with both hydrogen-bonding and base-stacking interactions favoring the planar G-tetrad geometry. Obviously, the charge state of an intercalating metal ion is as important as the ionic radius in forming a stable G4 structure. Thus, a delicate balance between these competing noncovalent interactions makes the chair-type antiparallel G4 structure of TBA selective for intercalating metal ions.
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Affiliation(s)
- Hyun Woo Kim
- Center for Molecular Modeling and Simulation, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
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17
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Sun L, Xie X, Weng W, Jin H. Structural and mechanistic insights into modified G-quadruplex thrombin-binding DNA aptamers. Biochem Biophys Res Commun 2019; 513:753-759. [PMID: 30992128 DOI: 10.1016/j.bbrc.2019.04.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 04/03/2019] [Indexed: 11/26/2022]
Abstract
Thrombin-binding aptamer (TBA) can fold into a G-quadruplex structure necessary for interacting with thrombin. When one thymidine residue of the TGT loop at position 7 is replaced with unlocked uracil (UNA), d-isothymidine (D-isoT) or l-isothymidine (L-isoT), these modified sequences display different activities. To date, the mechanisms of how D/L-isoT and UNA influence the biological properties of TBA have not been illustrated in the literature. In this paper, we fill this gap by probing the structure variations and binding modes of these modified TBAs via molecular dynamics (MD) simulation and free energy calculation. Comparative structural analyses demonstrated that both D-IsoT and UNA changed the local conformation of TGT loop and formed stronger interactions with the target protein. Particularly, D-IsoT and UNA adopted similar conformation which can well explain their similar biological activities. In addition, the flexibility of the two TT loops were described clearly. In contrast, L-IsoT at position 7 led to an obvious tendency to unfold. Free energy calculation and the analysis of key residues energy contributions eventually provide a clear picture of interactions for further understanding of the structure-activity relationships. Collectively, our findings open the way for a rational design of modified aptamers.
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Affiliation(s)
- Lidan Sun
- College of Chemical Engineering and Material Science, Quanzhou Normal University, Quanzhou, China.
| | - Xiaolan Xie
- College of Chemical Engineering and Material Science, Quanzhou Normal University, Quanzhou, China
| | - Wenting Weng
- College of Chemical Engineering and Material Science, Quanzhou Normal University, Quanzhou, China
| | - Hongwei Jin
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
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18
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Salsbury AM, Lemkul JA. Molecular Dynamics Simulations of the c-kit1 Promoter G-Quadruplex: Importance of Electronic Polarization on Stability and Cooperative Ion Binding. J Phys Chem B 2018; 123:148-159. [DOI: 10.1021/acs.jpcb.8b11026] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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19
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Havrila M, Stadlbauer P, Kührová P, Banáš P, Mergny JL, Otyepka M, Šponer J. Structural dynamics of propeller loop: towards folding of RNA G-quadruplex. Nucleic Acids Res 2018; 46:8754-8771. [PMID: 30165550 PMCID: PMC6158699 DOI: 10.1093/nar/gky712] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 07/03/2018] [Accepted: 07/27/2018] [Indexed: 02/04/2023] Open
Abstract
We have carried out an extended set of standard and enhanced-sampling MD simulations (for a cumulative simulation time of 620 μs) with the aim to study folding landscapes of the rGGGUUAGGG and rGGGAGGG parallel G-hairpins (PH) with propeller loop. We identify folding and unfolding pathways of the PH, which is bridged with the unfolded state via an ensemble of cross-like structures (CS) possessing mutually tilted or perpendicular G-strands interacting via guanine-guanine H-bonding. The oligonucleotides reach the PH conformation from the unfolded state via a conformational diffusion through the folding landscape, i.e. as a series of rearrangements of the H-bond interactions starting from compacted anti-parallel hairpin-like structures. Although isolated PHs do not appear to be thermodynamically stable we suggest that CS and PH-types of structures are sufficiently populated during RNA guanine quadruplex (GQ) folding within the context of complete GQ-forming sequences. These structures may participate in compact coil-like ensembles that involve all four G-strands and already some bound ions. Such ensembles can then rearrange into the fully folded parallel GQs via conformational diffusion. We propose that the basic atomistic folding mechanism of propeller loops suggested in this work may be common for their formation in RNA and DNA GQs.
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Affiliation(s)
- Marek Havrila
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
- Université de Bordeaux, INSERM U1212, CNRS UMR 5320, ARNA Laboratory, IECB, Pessac, France
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
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20
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Islam B, Stadlbauer P, Krepl M, Havrila M, Haider S, Sponer J. Structural Dynamics of Lateral and Diagonal Loops of Human Telomeric G-Quadruplexes in Extended MD Simulations. J Chem Theory Comput 2018; 14:5011-5026. [DOI: 10.1021/acs.jctc.8b00543] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Barira Islam
- Institute of Biophysics
of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics
of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics
of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Marek Havrila
- Institute of Biophysics
of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Shozeb Haider
- UCL School of
Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Jiri Sponer
- Institute of Biophysics
of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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21
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22
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Akhshi P, Wu G. Umbrella sampling molecular dynamics simulations reveal concerted ion movement through G-quadruplex DNA channels. Phys Chem Chem Phys 2018; 19:11017-11025. [PMID: 28327752 DOI: 10.1039/c7cp01028a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have applied the umbrella sampling (US) method in all-atom molecular dynamics (MD) simulations to obtain potential of mean force (PMF) profiles for ion transport through three representative G-quadruplex DNA channels: [d(TG4T)]4, [d(G3T4G4)]2, and d[G4(T4G4)3]. The US MD results are in excellent agreement with those obtained previously with the adaptive biasing force (ABF) method. We then utilized the unique features in the US MD method to investigate multi-ion effects in [d(G3T4G4)]2 and discovered that the concerted ion movement is crucial for fully explaining the unusual experimental results on ion movement in this particular G-quadruplex system. We anticipate that these modern free-energy methods will be useful tools in evaluating ion transport properties of other G-quadruplex DNA channels.
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Affiliation(s)
- Parisa Akhshi
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.
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23
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Abstract
Genomes contain rare guanine-rich sequences capable of assembling into four-stranded helical structures, termed G-quadruplexes, with potential roles in gene regulation and chromosome stability. Their mechanical unfolding has only been reported to date by all-atom simulations, which cannot dissect the major physical interactions responsible for their cohesion. Here, we propose a mesoscopic model to describe both the mechanical and thermal stability of DNA G-quadruplexes, where each nucleotide of the structure, as well as each central cation located at the inner channel, is mapped onto a single bead. In this framework we are able to simulate loading rates similar to the experimental ones, which are not reachable in simulations with atomistic resolution. In this regard, we present single-molecule force-induced unfolding experiments by a high-resolution optical tweezers on a DNA telomeric sequence capable of adopting a G-quadruplex conformation. Fitting the parameters of the model to the experiments we find a correct prediction of the rupture-force kinetics and a good agreement with previous near equilibrium measurements. Since G-quadruplex unfolding dynamics is halfway in complexity between secondary nucleic acids and tertiary protein structures, our model entails a nanoscale paradigm for non-equilibrium processes in the cell.
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Adrian M, Winnerdy FR, Heddi B, Phan AT. Rotation of Guanine Amino Groups in G-Quadruplexes: A Probe for Local Structure and Ligand Binding. Biophys J 2017; 113:775-784. [PMID: 28834714 DOI: 10.1016/j.bpj.2017.05.053] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 12/25/2022] Open
Abstract
Nucleic acids are dynamic molecules whose functions may depend on their conformational fluctuations and local motions. In particular, amino groups are dynamic components of nucleic acids that participate in the formation of various secondary structures such as G-quadruplexes. Here, we present a cost-efficient NMR method to quantify the rotational dynamics of guanine amino groups in G-quadruplex nucleic acids. An isolated spectrum of amino protons from a specific tetrad-bound guanine can be extracted from the nuclear Overhauser effect spectroscopy spectrum based on the close proximity between the intra-residue imino and amino protons. We apply the method in different structural contexts of G-quadruplexes and their complexes. Our results highlight the role of stacking and hydrogen-bond interactions in restraining amino-group rotation. The measurement of the rotation rate of individual amino groups could give insight into the dynamic processes occurring at specific locations within G-quadruplex nucleic acids, providing valuable probes for local structure, dynamics, and ligand binding.
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Affiliation(s)
- Michael Adrian
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Fernaldo Richtia Winnerdy
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Brahim Heddi
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Anh Tuân Phan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
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25
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Ramaswamy A, Smyrnova D, Froeyen M, Maiti M, Herdewijn P, Ceulemans A. Molecular Dynamics of Double Stranded Xylo-Nucleic Acid. J Chem Theory Comput 2017; 13:5028-5038. [PMID: 28742346 DOI: 10.1021/acs.jctc.7b00309] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Xylo-nucleic acid (XyloNA) is a synthetic analogue of ribo-nucleic acid (RNA), where the ribose sugar has been replaced by xylose. We present a molecular dynamics study of the conformational evolution of XyloNA double strand oligomers derived from A-RNA through the substitution of β-d-ribofuranose by β-d-xylofuranose and having lengths of 8, 16, and 29 base pairs, using a set of independent all-atom simulations performed at various time scales ranging from 55 to 100 ns, with one long 500 ns simulation of the 29-mer. In order to validate the robustness of XyloNA conformation, a set of simulations using various cutoff distances and solvation box dimensions has also been performed. These independent simulations reveal the uncoiling or elongation of the initial conformation to form an open ladder type transient state conformation and the subsequent formation of a highly flexible duplex with a tendency to coil in a left-handed fashion. The observed open ladder conformation is in line with recently obtained NMR data on the XyloNA 8-mer derived using 5'-d(GUGUACAC)-3'. The observed negative interbase pair twist leads to the observed highly flexible left-handed duplex, which is significantly less rigid than the stable left-handed dXyloNA duplex having a strong negative twist. A comparison between the xylo-analogues of DNA and RNA shows a clear distinction between the helical parameters, with implications for the pairing mechanism.
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Affiliation(s)
- Amutha Ramaswamy
- Laboratory for Quantum Chemistry, KULeuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium.,Centre for Bioinformatics, School of Life Sciences, Pondicherry University , Puducherry 605014, India
| | - Daryna Smyrnova
- Laboratory for Quantum Chemistry, KULeuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Mathy Froeyen
- Laboratory for Medicinal Chemistry, KULeuven , Herestraat 49, B-3000 Leuven, Belgium
| | - Mohitosh Maiti
- Laboratory for Medicinal Chemistry, KULeuven , Herestraat 49, B-3000 Leuven, Belgium
| | - Piet Herdewijn
- Laboratory for Medicinal Chemistry, KULeuven , Herestraat 49, B-3000 Leuven, Belgium
| | - Arnout Ceulemans
- Laboratory for Quantum Chemistry, KULeuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium
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26
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Havrila M, Stadlbauer P, Islam B, Otyepka M, Šponer J. Effect of Monovalent Ion Parameters on Molecular Dynamics Simulations of G-Quadruplexes. J Chem Theory Comput 2017; 13:3911-3926. [PMID: 28657760 DOI: 10.1021/acs.jctc.7b00257] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
G-quadruplexes (GQs) are key noncanonical DNA and RNA architectures stabilized by desolvated monovalent cations present in their central channels. We analyze extended atomistic molecular dynamics simulations (∼580 μs in total) of GQs with 11 monovalent cation parametrizations, assessing GQ overall structural stability, dynamics of internal cations, and distortions of the G-tetrad geometries. Majority of simulations were executed with the SPC/E water model; however, test simulations with TIP3P and OPC water models are also reported. The identity and parametrization of ions strongly affect behavior of a tetramolecular d[GGG]4 GQ, which is unstable with several ion parametrizations. The remaining studied RNA and DNA GQs are structurally stable, though the G-tetrad geometries are always deformed by bifurcated H-bonding in a parametrization-specific manner. Thus, basic 10-μs-scale simulations of fully folded GQs can be safely done with a number of cation parametrizations. However, there are parametrization-specific differences and basic force-field errors affecting the quantitative description of ion-tetrad interactions, which may significantly affect studies of the ion-binding processes and description of the GQ folding landscape. Our d[GGG]4 simulations indirectly suggest that such studies will also be sensitive to the water models. During exchanges with bulk water, the Na+ ions move inside the GQs in a concerted manner, while larger relocations of the K+ ions are typically separated. We suggest that the Joung-Cheatham SPC/E K+ parameters represent a safe choice in simulation studies of GQs, though variation of ion parameters can be used for specific simulation goals.
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Affiliation(s)
- Marek Havrila
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University , Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Barira Islam
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University , Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
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27
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Islam B, Stadlbauer P, Gil-Ley A, Pérez-Hernández G, Haider S, Neidle S, Bussi G, Banas P, Otyepka M, Sponer J. Exploring the Dynamics of Propeller Loops in Human Telomeric DNA Quadruplexes Using Atomistic Simulations. J Chem Theory Comput 2017; 13:2458-2480. [PMID: 28475322 PMCID: PMC5514396 DOI: 10.1021/acs.jctc.7b00226] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
![]()
We
have carried out a series of extended unbiased molecular dynamics
(MD) simulations (up to 10 μs long, ∼162 μs in
total) complemented by replica-exchange with the collective variable
tempering (RECT) approach for several human telomeric DNA G-quadruplex
(GQ) topologies with TTA propeller loops. We used different AMBER
DNA force-field variants and also processed simulations by Markov
State Model (MSM) analysis. The slow conformational transitions in
the propeller loops took place on a scale of a few μs, emphasizing
the need for long simulations in studies of GQ dynamics. The propeller
loops sampled similar ensembles for all GQ topologies and for all
force-field dihedral-potential variants. The outcomes of standard
and RECT simulations were consistent and captured similar spectrum
of loop conformations. However, the most common crystallographic loop
conformation was very unstable with all force-field versions. Although
the loss of canonical γ-trans state of the
first propeller loop nucleotide could be related to the indispensable
bsc0 α/γ dihedral potential, even supporting this particular
dihedral by a bias was insufficient to populate the experimentally
dominant loop conformation. In conclusion, while our simulations were
capable of providing a reasonable albeit not converged sampling of
the TTA propeller loop conformational space, the force-field description
still remained far from satisfactory.
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Affiliation(s)
- Barira Islam
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Guillermo Pérez-Hernández
- Department for Mathematics and Computer Science, Freie Universität Berlin , Arnimallee 6, Berlin 14195, Germany
| | - Shozeb Haider
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Stephen Neidle
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Pavel Banas
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Jiri Sponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
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28
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Rebič M, Mocci F, Uličný J, Lyubartsev AP, Laaksonen A. Coarse-Grained Simulation of Rodlike Higher-Order Quadruplex Structures at Different Salt Concentrations. ACS OMEGA 2017; 2:386-396. [PMID: 31457446 PMCID: PMC6641151 DOI: 10.1021/acsomega.6b00419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/19/2017] [Indexed: 05/03/2023]
Abstract
We present a coarse-grained (CG) model of a rodlike higher-order quadruplex with explicit monovalent salts, which was developed from radial distribution functions of an underlying reference atomistic molecular dynamics simulation using inverse Monte Carlo technique. This work improves our previous CG model and extends its applicability beyond the minimal salt conditions, allowing its use at variable ionic strengths. The strategies necessary for the model development are clearly explained and discussed. The effects of the number of stacked quadruplexes and varied salt concentration on the elasticity of the rodlike higher-order quadruplex structures are analyzed. The CG model reproduces the deformations of the terminal parts in agreement with experimental observations without introducing any special parameters for terminal beads and reveals slight differences in the rise and twist of the G-quartet arrangement along the studied biopolymer. The conclusions of our study can be generalized for other G-quartet-based structures.
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Affiliation(s)
- Matúš Rebič
- Division
of Physical Chemistry, Department of Materials and Environmental Chemistry,
Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
- Department of Biophysics, Faculty
of Science and Centre for Multimodal Imaging (CMI),
Department of Biophysics, Institute of Physics, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia
- Science
for Life Laboratory (SciLifeLab), 17121 Solna, Sweden
| | - Francesca Mocci
- Division
of Physical Chemistry, Department of Materials and Environmental Chemistry,
Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
- Science
for Life Laboratory (SciLifeLab), 17121 Solna, Sweden
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
| | - Jozef Uličný
- Department of Biophysics, Faculty
of Science and Centre for Multimodal Imaging (CMI),
Department of Biophysics, Institute of Physics, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia
| | - Alexander P. Lyubartsev
- Division
of Physical Chemistry, Department of Materials and Environmental Chemistry,
Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Aatto Laaksonen
- Division
of Physical Chemistry, Department of Materials and Environmental Chemistry,
Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
- Science
for Life Laboratory (SciLifeLab), 17121 Solna, Sweden
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
- Stellenbosch
Institute of Advanced Study (STIAS), Wallenberg
Research Centre at Stellenbosch University, 7600 Stellenbosch, South Africa
- E-mail: . Phone: +46 8 162372 (A.L.)
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29
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Šponer J, Bussi G, Stadlbauer P, Kührová P, Banáš P, Islam B, Haider S, Neidle S, Otyepka M. Folding of guanine quadruplex molecules-funnel-like mechanism or kinetic partitioning? An overview from MD simulation studies. Biochim Biophys Acta Gen Subj 2016; 1861:1246-1263. [PMID: 27979677 DOI: 10.1016/j.bbagen.2016.12.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/04/2016] [Accepted: 12/11/2016] [Indexed: 01/18/2023]
Abstract
BACKGROUND Guanine quadruplexes (GQs) play vital roles in many cellular processes and are of much interest as drug targets. In contrast to the availability of many structural studies, there is still limited knowledge on GQ folding. SCOPE OF REVIEW We review recent molecular dynamics (MD) simulation studies of the folding of GQs, with an emphasis paid to the human telomeric DNA GQ. We explain the basic principles and limitations of all types of MD methods used to study unfolding and folding in a way accessible to non-specialists. We discuss the potential role of G-hairpin, G-triplex and alternative GQ intermediates in the folding process. We argue that, in general, folding of GQs is fundamentally different from funneled folding of small fast-folding proteins, and can be best described by a kinetic partitioning (KP) mechanism. KP is a competition between at least two (but often many) well-separated and structurally different conformational ensembles. MAJOR CONCLUSIONS The KP mechanism is the only plausible way to explain experiments reporting long time-scales of GQ folding and the existence of long-lived sub-states. A significant part of the natural partitioning of the free energy landscape of GQs comes from the ability of the GQ-forming sequences to populate a large number of syn-anti patterns in their G-tracts. The extreme complexity of the KP of GQs typically prevents an appropriate description of the folding landscape using just a few order parameters or collective variables. GENERAL SIGNIFICANCE We reconcile available computational and experimental studies of GQ folding and formulate basic principles characterizing GQ folding landscapes. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Barira Islam
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Shozeb Haider
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Stephen Neidle
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
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30
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Stadlbauer P, Mazzanti L, Cragnolini T, Wales DJ, Derreumaux P, Pasquali S, Šponer J. Coarse-Grained Simulations Complemented by Atomistic Molecular Dynamics Provide New Insights into Folding and Unfolding of Human Telomeric G-Quadruplexes. J Chem Theory Comput 2016; 12:6077-6097. [DOI: 10.1021/acs.jctc.6b00667] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Petr Stadlbauer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
- Regional
Centre of Advanced Technologies and Materials, Departments of Physical
Chemistry, Faculty of Science, Palacký University, 17. listopadu
1192/12, 771 46 Olomouc, Czech Republic
| | - Liuba Mazzanti
- Laboratoire
de Biochimie Théorique, IBPC, CNRS UPR9080, Université Sorbonne Paris Cite, Paris Diderot, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Tristan Cragnolini
- Department
of Chemistry, Cambridge University, Lensfield Road, Cambridge CB2 1EW, U.K
| | - David J. Wales
- Department
of Chemistry, Cambridge University, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Philippe Derreumaux
- Laboratoire
de Biochimie Théorique, IBPC, CNRS UPR9080, Université Sorbonne Paris Cite, Paris Diderot, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Samuela Pasquali
- Laboratoire
de Biochimie Théorique, IBPC, CNRS UPR9080, Université Sorbonne Paris Cite, Paris Diderot, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Jiří Šponer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
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31
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Rebič M, Laaksonen A, Šponer J, Uličný J, Mocci F. Molecular Dynamics Simulation Study of Parallel Telomeric DNA Quadruplexes at Different Ionic Strengths: Evaluation of Water and Ion Models. J Phys Chem B 2016; 120:7380-91. [PMID: 27379924 DOI: 10.1021/acs.jpcb.6b06485] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Most molecular dynamics (MD) simulations of DNA quadruplexes have been performed under minimal salt conditions using the Åqvist potential parameters for the cation with the TIP3P water model. Recently, this combination of parameters has been reported to be problematic for the stability of quadruplex DNA, especially caused by the ion interactions inside or near the quadruplex channel. Here, we verify how the choice of ion parameters and water model can affect the quadruplex structural stability and the interactions with the ions outside the channel. We have performed a series of MD simulations of the human full-parallel telomeric quadruplex by neutralizing its negative charge with K(+) ions. Three combinations of different cation potential parameters and water models have been used: (a) Åqvist ion parameters, TIP3P water model; (b) Joung and Cheatham ion parameters, TIP3P water model; and (c) Joung and Cheatham ion parameters, TIP4Pew water model. For the combinations (b) and (c), the effect of the ionic strength has been evaluated by adding increasing amounts of KCl salt (50, 100, and 200 mM). Two independent simulations using the Åqvist parameters with the TIP3P model show that this combination is clearly less suited for the studied quadruplex with K(+) as counterions. In both simulations, one ion escapes from the channel, followed by significant deformation of the structure, leading to deviating conformation compared to that in the reference crystallographic data. For the other combinations of ion and water potentials, no tendency is observed for the channel ions to escape from the quadruplex channel. In addition, the internal mobility of the three loops, torsion angles, and counterion affinity have been investigated at varied salt concentrations. In summary, the selection of ion and water models is crucial as it can affect both the structure and dynamics as well as the interactions of the quadruplex with its counterions. The results obtained with the TIP4Pew model are found to be closest to the experimental data at all of the studied ion concentrations.
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Affiliation(s)
- Matúš Rebič
- Department of Materials and Environmental Chemistry, Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University , 10691 Stockholm, Sweden.,Science for Life Laboratory (SciLifelab) , 17121 Solna, Sweden
| | - Aatto Laaksonen
- Department of Materials and Environmental Chemistry, Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University , 10691 Stockholm, Sweden.,Science for Life Laboratory (SciLifelab) , 17121 Solna, Sweden.,Stellenbosch Institute of Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University , 7600 Stellenbosch, South Africa.,Department of Chemical and Geological Sciences, University of Cagliari , I-09042 Monserrato, Italy
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic (AVČR) , Kralovopolska 135, 612 65 Brno, Czech Republic.,Central European Institute of Technology (CEITEC) , Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | | | - Francesca Mocci
- Department of Materials and Environmental Chemistry, Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University , 10691 Stockholm, Sweden.,Science for Life Laboratory (SciLifelab) , 17121 Solna, Sweden.,Department of Chemical and Geological Sciences, University of Cagliari , I-09042 Monserrato, Italy
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32
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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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33
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Kogut M, Kleist C, Czub J. Molecular dynamics simulations reveal the balance of forces governing the formation of a guanine tetrad-a common structural unit of G-quadruplex DNA. Nucleic Acids Res 2016; 44:3020-30. [PMID: 26980278 PMCID: PMC4838382 DOI: 10.1093/nar/gkw160] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/01/2016] [Indexed: 12/13/2022] Open
Abstract
G-quadruplexes (G4) are nucleic acid conformations of guanine-rich sequences, in which guanines are arranged in the square-planar G-tetrads, stacked on one another. G4 motifs form in vivo and are implicated in regulation of such processes as gene expression and chromosome maintenance. The structure and stability of various G4 topologies were determined experimentally; however, the driving forces for their formation are not fully understood at the molecular level. Here, we used all-atom molecular dynamics to probe the microscopic origin of the G4 motif stability. By computing the free energy profiles governing the dissociation of the 3′-terminal G-tetrad in the telomeric parallel-stranded G4, we examined the thermodynamic and kinetic stability of a single G-tetrad, as a common structural unit of G4 DNA. Our results indicate that the energetics of guanine association alone does not explain the overall stability of the G-tetrad and that interactions involving sugar–phosphate backbone, in particular, the constrained minimization of the phosphate–phosphate repulsion energy, are crucial in providing the observed enthalpic stabilization. This enthalpic gain is largely compensated by the unfavorable entropy change due to guanine association and optimization of the backbone topology.
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Affiliation(s)
- Mateusz Kogut
- Department of Physical Chemistry, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Cyprian Kleist
- Department of Physical Chemistry, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Jacek Czub
- Department of Physical Chemistry, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland
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34
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Islam B, Stadlbauer P, Neidle S, Haider S, Sponer J. Can We Execute Reliable MM-PBSA Free Energy Computations of Relative Stabilities of Different Guanine Quadruplex Folds? J Phys Chem B 2016; 120:2899-912. [DOI: 10.1021/acs.jpcb.6b01059] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Barira Islam
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
| | - Stephen Neidle
- UCL School of Pharmacy, 29-39
Brunswick Square, London WC1N 1AX, U.K
| | - Shozeb Haider
- UCL School of Pharmacy, 29-39
Brunswick Square, London WC1N 1AX, U.K
| | - Jiri Sponer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
- CEITEC
- Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
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35
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Gkionis K, Kruse H, Šponer J. Derivation of Reliable Geometries in QM Calculations of DNA Structures: Explicit Solvent QM/MM and Restrained Implicit Solvent QM Optimizations of G-Quadruplexes. J Chem Theory Comput 2016; 12:2000-16. [DOI: 10.1021/acs.jctc.5b01025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Konstantinos Gkionis
- Institute of Biophysics,
Academy of Sciences of the Czech Republic, Královopolská 135, 612
65 Brno, Czech Republic
| | - Holger Kruse
- Institute of Biophysics,
Academy of Sciences of the Czech Republic, Královopolská 135, 612
65 Brno, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics,
Academy of Sciences of the Czech Republic, Královopolská 135, 612
65 Brno, Czech Republic
- CEITEC
− Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
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36
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Russo Krauss I, Ramaswamy S, Neidle S, Haider S, Parkinson GN. Structural Insights into the Quadruplex-Duplex 3' Interface Formed from a Telomeric Repeat: A Potential Molecular Target. J Am Chem Soc 2016; 138:1226-33. [PMID: 26730610 DOI: 10.1021/jacs.5b10492] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We report here on an X-ray crystallographic and molecular modeling investigation into the complex 3' interface formed between putative parallel stranded G-quadruplexes and a duplex DNA sequence constructed from the human telomeric repeat sequence TTAGGG. Our crystallographic approach provides a detailed snapshot of a telomeric 3' quadruplex-duplex junction: a junction that appears to have the potential to form a unique molecular target for small molecule binding and interference with telomere-related functions. This unique target is particularly relevant as current high-affinity compounds that bind putative G-quadruplex forming sequences only rarely have a high degree of selectivity for a particular quadruplex. Here DNA junctions were assembled using different putative quadruplex-forming scaffolds linked at the 3' end to a telomeric duplex sequence and annealed to a complementary strand. We successfully generated a series of G-quadruplex-duplex containing crystals, both alone and in the presence of ligands. The structures demonstrate the formation of a parallel folded G-quadruplex and a B-form duplex DNA stacked coaxially. Most strikingly, structural data reveals the consistent formation of a TAT triad platform between the two motifs. This triad allows for a continuous stack of bases to link the quadruplex motif with the duplex region. For these crystal structures formed in the absence of ligands, the TAT triad interface occludes ligand binding at the 3' quadruplex-duplex interface, in agreement with in silico docking predictions. However, with the rearrangement of a single nucleotide, a stable pocket can be produced, thus providing an opportunity for the binding of selective molecules at the interface.
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Affiliation(s)
- Irene Russo Krauss
- Department of Chemical Sciences, University of Naples Federico II , I-80126 Napoli, Italy
| | - Sneha Ramaswamy
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Stephen Neidle
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Shozeb Haider
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Gary N Parkinson
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
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37
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Largy E, Mergny JL, Gabelica V. Role of Alkali Metal Ions in G-Quadruplex Nucleic Acid Structure and Stability. Met Ions Life Sci 2016; 16:203-58. [PMID: 26860303 DOI: 10.1007/978-3-319-21756-7_7] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G-quadruplexes are guanine-rich nucleic acids that fold by forming successive quartets of guanines (the G-tetrads), stabilized by intra-quartet hydrogen bonds, inter-quartet stacking, and cation coordination. This specific although highly polymorphic type of secondary structure deviates significantly from the classical B-DNA duplex. G-quadruplexes are detectable in human cells and are strongly suspected to be involved in a number of biological processes at the DNA and RNA levels. The vast structural polymorphism exhibited by G-quadruplexes, together with their putative biological relevance, makes them attractive therapeutic targets compared to canonical duplex DNA. This chapter focuses on the essential and specific coordination of alkali metal cations by G-quadruplex nucleic acids, and most notably on studies highlighting cation-dependent dissimilarities in their stability, structure, formation, and interconversion. Section 1 surveys G-quadruplex structures and their interactions with alkali metal ions while Section 2 presents analytical methods used to study G-quadruplexes. The influence of alkali cations on the stability, structure, and kinetics of formation of G-quadruplex structures of quadruplexes will be discussed in Sections 3 and 4. Section 5 focuses on the cation-induced interconversion of G-quadruplex structures. In Sections 3 to 5, we will particularly emphasize the comparisons between cations, most often K(+) and Na(+) because of their prevalence in the literature and in cells.
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Affiliation(s)
- Eric Largy
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France.,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France
| | - Jean-Louis Mergny
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France. .,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France.
| | - Valérie Gabelica
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France. .,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France.
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Ray A, Panigrahi S, Bhattacharyya D. A comparison of four different conformations adopted by human telomeric G-quadruplex using computer simulations. Biopolymers 2015; 105:83-99. [PMID: 26448055 DOI: 10.1002/bip.22751] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 10/01/2015] [Accepted: 10/03/2015] [Indexed: 01/06/2023]
Abstract
The telomeric G-quadruplexes for their unique structural features are considered as potential anticancer drug targets. These, however, exhibit structural polymorphism as different topology types for the intra-molecular G-quadruplexes from human telomeric G-rich sequences have been reported based on NMR spectroscopy and X-ray crystallography. These techniques provide detailed atomic-level information about the molecule but relative conformational stability of the different topologies remains unsolved. Therefore, to understand the conformational preference, we have carried out quantum chemical calculations on G-quartets; used all-atom molecular dynamics (MD) simulations and steered molecular dynamics (SMD) simulations to characterize the four human telomeric G-quadruplex topologies based on its G-tetrad core-types, viz., parallel, anti-parallel, mixed-(3 + 1)-form1 and mixed-(3 + 1)-form2. We have also studied a non-telomeric sequence along with these telomeric forms giving a comparison between the two G-rich forms. The structural properties such as base pairing, stacking geometry and backbone conformations have been analyzed. The quantum calculations indicate that presence of a sodium ion inside the G-tetrad plane or two potassium ions on both sides of the plane give it an overall planarity which is much needed for good stacking to form a helix. MD simulations indicate that capping of the G-tetrad core by the TTA loops keep the terminal guanine bases away from water. The SMD simulations along with equilibrium MD studies indicate that the parallel and non-telomeric forms are comparatively less stable. We could come to the conclusion that the anti-parallel form and also the mixed-(3 + 1)-form1 topology are most likely to represent the major conformation., 2016. © 2015 Wiley Periodicals, Inc. Biopolymers 105: 83-99, 2016.
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Affiliation(s)
- Angana Ray
- Computational Science Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India
| | - Swati Panigrahi
- Computational Science Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India
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Stadlbauer P, Kührová P, Banáš P, Koča J, Bussi G, Trantírek L, Otyepka M, Šponer J. Hairpins participating in folding of human telomeric sequence quadruplexes studied by standard and T-REMD simulations. Nucleic Acids Res 2015; 43:9626-44. [PMID: 26433223 PMCID: PMC4787745 DOI: 10.1093/nar/gkv994] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/22/2015] [Indexed: 11/13/2022] Open
Abstract
DNA G-hairpins are potential key structures participating in folding of human telomeric guanine quadruplexes (GQ). We examined their properties by standard MD simulations starting from the folded state and long T-REMD starting from the unfolded state, accumulating ∼130 μs of atomistic simulations. Antiparallel G-hairpins should spontaneously form in all stages of the folding to support lateral and diagonal loops, with sub-μs scale rearrangements between them. We found no clear predisposition for direct folding into specific GQ topologies with specific syn/anti patterns. Our key prediction stemming from the T-REMD is that an ideal unfolded ensemble of the full GQ sequence populates all 4096 syn/anti combinations of its four G-stretches. The simulations can propose idealized folding pathways but we explain that such few-state pathways may be misleading. In the context of the available experimental data, the simulations strongly suggest that the GQ folding could be best understood by the kinetic partitioning mechanism with a set of deep competing minima on the folding landscape, with only a small fraction of molecules directly folding to the native fold. The landscape should further include non-specific collapse processes where the molecules move via diffusion and consecutive random rare transitions, which could, e.g. structure the propeller loops.
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Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jaroslav Koča
- CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic National Center for Biomolecular Research, Faculty of Science, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Lukáš Trantírek
- CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
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Islam B, Stadlbauer P, Krepl M, Koca J, Neidle S, Haider S, Sponer J. Extended molecular dynamics of a c-kit promoter quadruplex. Nucleic Acids Res 2015; 43:8673-93. [PMID: 26245347 PMCID: PMC4605300 DOI: 10.1093/nar/gkv785] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 07/21/2015] [Indexed: 01/29/2023] Open
Abstract
The 22-mer c-kit promoter sequence folds into a parallel-stranded quadruplex with a unique structure, which has been elucidated by crystallographic and NMR methods and shows a high degree of structural conservation. We have carried out a series of extended (up to 10 μs long, ∼50 μs in total) molecular dynamics simulations to explore conformational stability and loop dynamics of this quadruplex. Unfolding no-salt simulations are consistent with a multi-pathway model of quadruplex folding and identify the single-nucleotide propeller loops as the most fragile part of the quadruplex. Thus, formation of propeller loops represents a peculiar atomistic aspect of quadruplex folding. Unbiased simulations reveal μs-scale transitions in the loops, which emphasizes the need for extended simulations in studies of quadruplex loops. We identify ion binding in the loops which may contribute to quadruplex stability. The long lateral-propeller loop is internally very stable but extensively fluctuates as a rigid entity. It creates a size-adaptable cleft between the loop and the stem, which can facilitate ligand binding. The stability gain by forming the internal network of GA base pairs and stacks of this loop may be dictating which of the many possible quadruplex topologies is observed in the ground state by this promoter quadruplex.
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Affiliation(s)
- Barira Islam
- Central European Institute of Technology (CEITEC), Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Jaroslav Koca
- Central European Institute of Technology (CEITEC), Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic National Center for Biomolecular Research, Faculty of Science, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Stephen Neidle
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Shozeb Haider
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Jiri Sponer
- Central European Institute of Technology (CEITEC), Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
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Bergues-Pupo AE, Arias-Gonzalez JR, Morón MC, Fiasconaro A, Falo F. Role of the central cations in the mechanical unfolding of DNA and RNA G-quadruplexes. Nucleic Acids Res 2015; 43:7638-47. [PMID: 26170233 PMCID: PMC4551928 DOI: 10.1093/nar/gkv690] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/23/2015] [Indexed: 12/20/2022] Open
Abstract
Cations are known to mediate diverse interactions in nucleic acids duplexes but they are critical in the arrangement of four-stranded structures. Here, we use all-atom molecular dynamics simulations with explicit solvent to analyse the mechanical unfolding of representative intramolecular G-quadruplex structures: a parallel, a hybrid and an antiparallel DNA and a parallel RNA, in the presence of stabilising cations. We confirm the stability of these conformations in the presence of \documentclass[12pt]{minimal}
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}{}$\rm {K}^+$\end{document} central ions and observe distortions from the tetrad topology in their absence. Force-induced unfolding dynamics is then investigated. We show that the unfolding events in the force-extension curves are concomitant to the loss of coordination between the central ions and the guanines of the G-quadruplex. We found lower ruptures forces for the parallel configuration with respect to the antiparallel one, while the behaviour of the force pattern of the parallel RNA appears similar to the parallel DNA. We anticipate that our results will be essential to interpret the fine structure rupture profiles in stretching assays at high resolution and will shed light on the mechanochemical activity of G-quadruplex-binding machinery.
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Affiliation(s)
- Ana Elisa Bergues-Pupo
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Mariano Esquillor, 50018 Zaragoza, Spain Departamento de Física, Universidad de Oriente, 90500 Santiago de Cuba, Cuba
| | - J Ricardo Arias-Gonzalez
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Cantoblanco, 28049 Madrid, Spain CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología, Madrid, Spain'
| | - María Carmen Morón
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain Instituto de Ciencia de Materiales de Aragón (ICMA), Consejo Superior de Investigaciones Científicas, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Alessandro Fiasconaro
- School of Mathematical Sciences, Queen Mary University of London - Mile End Road, London E1 4NS, UK
| | - Fernando Falo
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Mariano Esquillor, 50018 Zaragoza, Spain
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Iacovelli F, Falconi M. Decoding the conformation-linked functional properties of nucleic acids by the use of computational tools. FEBS J 2015; 282:3298-310. [DOI: 10.1111/febs.13315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/16/2015] [Accepted: 04/29/2015] [Indexed: 12/25/2022]
Affiliation(s)
| | - Mattia Falconi
- Department of Biology; University of Rome “Tor Vergata”; Italy
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Arba M, Kartasasmita RE, Tjahjono DH. Molecular docking and dynamics simulations on the interaction of cationic porphyrin-anthraquinone hybrids with DNA G-quadruplexes. J Biomol Struct Dyn 2015; 34:427-38. [PMID: 25808513 DOI: 10.1080/07391102.2015.1033015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A series of cationic porphyrin-anthraquinone hybrids bearing either pyridine, imidazole, or pyrazole rings at the meso-positions have been investigated for their interaction with DNA G-quadruplexes by employing molecular docking and molecular dynamics simulations. Three types of DNA G-quadruplexes were utilized, which comprise parallel, antiparallel, and mixed hybrid topologies. The porphyrin hybrids have a preference to bind with parallel and mixed hybrid structures compared to the antiparallel structure. This preference arises from the end stacking of porphyrin moiety following G-stem and loop binding of anthraquinone tail, which is not found in the antiparallel due to the presence of diagonal and lateral loops that crowd the G-quartet. The binding to the antiparallel, instead, occurred with poorer affinity through both the loop and wide groove. All sites of porphyrin binding were confirmed by 6 ns molecular dynamics simulation, as well as by the negative value of the total binding free energies that were calculated using the MMPBSA method. Free energy analysis shows that the favorable contribution came from the electrostatic term, which supposedly originated from the interaction of either cationic pyridinium, pyrazole, or imidazole groups and the anionic phosphate backbone, and also from the van der Waals energy, which primarily contributed through end stacking interaction.
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Affiliation(s)
- Muhammad Arba
- a School of Pharmacy , Bandung Institute of Technology , Jalan Ganesha 10, Bandung 40132 , Indonesia.,b Department of Chemistry , Halu Oleo University , Jl. HEA Mokodompit, Kendari 93232 , Indonesia
| | - Rahmana E Kartasasmita
- a School of Pharmacy , Bandung Institute of Technology , Jalan Ganesha 10, Bandung 40132 , Indonesia
| | - Daryono H Tjahjono
- a School of Pharmacy , Bandung Institute of Technology , Jalan Ganesha 10, Bandung 40132 , Indonesia
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44
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Collie GW, Campbell NH, Neidle S. Loop flexibility in human telomeric quadruplex small-molecule complexes. Nucleic Acids Res 2015; 43:4785-99. [PMID: 25940631 PMCID: PMC4446451 DOI: 10.1093/nar/gkv427] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/20/2015] [Indexed: 01/25/2023] Open
Abstract
Quadruplex nucleic acids can be formed at the ends of eukaryotic chromosomes. Their formation and stabilisation by appropriate small molecules can be used as a means of inhibiting the telomere maintenance functions of telomerase in human cancer cells. The crystal structures have been determined for a number of complexes between these small molecules and human telomeric DNA and RNA quadruplexes. The detailed structural characteristics of these complexes have been surveyed here and the variations in conformation for the TTA and UUA loops have been explored. Loop conformations have been classified in terms of a number of discrete types and their distribution among the crystal structures. Sugar conformation and backbone angles have also been examined and trends highlighted. One particular loop class has been found to be most prevalent. Implications for in particular, rational drug design, are discussed.
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Affiliation(s)
- Gavin W Collie
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Nancy H Campbell
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Stephen Neidle
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
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Lech CJ, Phan AT, Michel-Beyerle ME, Voityuk AA. Influence of base stacking geometry on the nature of excited states in G-quadruplexes: a time-dependent DFT study. J Phys Chem B 2015; 119:3697-705. [PMID: 25654765 DOI: 10.1021/jp512767j] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
G-quadruplexes are four-stranded structures of nucleic acids that are formed from the association of guanine nucleobases into cyclical arrangements known as tetrads. G-quadruplexes are involved in a host of biological processes and are of interest in nanomaterial applications. However, not much is known about their electronic properties. In this paper, we analyze electronic excited states of G-quadruplexes using a combination of time-dependent DFT calculations and molecular dynamics simulations. We systematically consider experimentally observed arrangements of stacked guanine tetrads. The effects of structural features on exciton delocalization and photoinduced charge separation are explored using a quantitative analysis of the transition electron density. It is shown that collective coherent excitations shared between two guanine nucleobases dominate in the absorption spectrum of stacked G-tetrads. These excitations may also include a significant contribution of charge transfer states. Large variation in exciton localization is also observed between different structures with a general propensity toward localization between two bases. We reveal large differences in how charge separation occurs within different nucleobase arrangements, with some geometries favoring separation within a single tetrad and others favoring separation between tetrads. We also investigate the effects of the coordinating K(+) ion located in the central cavity of G-quadruplexes on the relative excited state properties of such systems. Our results demonstrate how the nature of excited states in G-quadruplexes depends on the nucleobase stacking geometry resulting from the mutual arrangement of guanine tetrads.
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Affiliation(s)
- Christopher J Lech
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371, Singapore
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Ghosh S, Jana J, Kar RK, Chatterjee S, Dasgupta D. Plant alkaloid chelerythrine induced aggregation of human telomere sequence--a unique mode of association between a small molecule and a quadruplex. Biochemistry 2015; 54:974-86. [PMID: 25566806 DOI: 10.1021/bi501117x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Small molecules that interact with G-quadruplex structures formed by the human telomeric region and stabilize them have the potential to evolve as anticancer therapeutic agents. Herein we report the interaction of a putative anticancer agent from a plant source, chelerythrine, with the human telomeric DNA sequence. It has telomerase inhibitory potential as demonstrated from telomerase repeat amplification assay in cancer cell line extract. We have attributed this to the quadruplex binding potential of the molecule and characterized the molecular details of the interaction by means of optical spectroscopy such as absorbance and circular dichroism and calorimetric techniques such as isothermal titration calorimetry and differential scanning calorimetry. The results show that chelerythrine binds with micromolar dissociation constant and 2:1 binding stoichiometry to the human telomeric DNA sequence. Chelerythrine association stabilizes the G-quadruplex. Nuclear magnetic resonance spectroscopy ((1)H and (31)P) shows that chelerythrine binds to both G-quartet and phosphate backbone of the quadruplex leading to quadruplex aggregation. Molecular dynamics simulation studies support the above inferences and provide further insight into the mechanism of ligand binding. The specificity toward quartet binding for chelerythrine is higher compared to that of groove binding. MM-PBSA calculation mines out the energy penalty for quartet binding to be -4.7 kcal/mol, whereas that of the groove binding is -1.7 kcal/mol. We propose that the first chelerythrine molecule binds to the quartet followed by a second molecule which binds to the groove. This second molecule might bring about aggregation of the quadruplex structure which is evident from the results of nuclear magnetic resonance.
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Affiliation(s)
- Saptaparni Ghosh
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics , Block-AF, Sector-I, Bidhannagar, Kolkata-700064, India
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Ali A, Bansal M, Bhattacharya S. Ligand 5,10,15,20-tetra(N-methyl-4-pyridyl)porphine (TMPyP4) prefers the parallel propeller-type human telomeric G-quadruplex DNA over its other polymorphs. J Phys Chem B 2014; 119:5-14. [PMID: 25526532 DOI: 10.1021/jp505792z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The binding of ligand 5,10,15,20-tetra(N-methyl-4-pyridyl)porphine (TMPyP4) with telomeric and genomic G-quadruplex DNA has been extensively studied. However, a comparative study of interactions of TMPyP4 with different conformations of human telomeric G-quadruplex DNA, namely, parallel propeller-type (PP), antiparallel basket-type (AB), and mixed hybrid-type (MH) G-quadruplex DNA, has not been done. We considered all the possible binding sites in each of the G-quadruplex DNA structures and docked TMPyP4 to each one of them. The resultant most potent sites for binding were analyzed from the mean binding free energy of the complexes. Molecular dynamics simulations were then carried out, and analysis of the binding free energy of the TMPyP4-G-quadruplex complex showed that the binding of TMPyP4 with parallel propeller-type G-quadruplex DNA is preferred over the other two G-quadruplex DNA conformations. The results obtained from the change in solvent excluded surface area (SESA) and solvent accessible surface area (SASA) also support the more pronounced binding of the ligand with the parallel propeller-type G-quadruplex DNA.
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Affiliation(s)
- Asfa Ali
- Department of Organic Chemistry, Indian Institute of Science , Bangalore 560 012, India
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Rebič M, Mocci F, Laaksonen A, Uličný J. Multiscale simulations of human telomeric G-quadruplex DNA. J Phys Chem B 2014; 119:105-13. [PMID: 25469629 DOI: 10.1021/jp5103274] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We present a coarse-grain (CG) model of human telomeric G-quadruplex, obtained using the inverse Monte Carlo (IMC) and iterative Boltzmann inversion (IBI) techniques implemented within the software package called MagiC. As a starting point, the 2HY9 human telomeric [3 + 1] hybrid, a 26-nucleobase sequence, was modeled performing a 1 μs long atomistic molecular dynamics (MD) simulation. The chosen quadruplex includes two kinds of loops and all possible combinations of relative orientations of guanine strands that can be found in quadruplexes. The effective CG potential for a one bead per nucleotide model has been developed from the radial distribution functions of this reference system. The obtained potentials take into account explicitly the interaction with counterions, while the effect of the solvent is included implicitly. The structural properties of the obtained CG model of the quadruplex provided a perfect match to those resulting from the reference atomistic MD simulation. The same set of interaction potentials was then used to simulate at the CG level another quadruplex topology (PDB id 1KF1 ) that can be formed by the human telomeric DNA sequence. This quadruplex differs from 2HY9 in the loop topology and G-strand relative orientation. The results of the CG MD simulations of 1KF1 are very encouraging and suggest that the CG model based on 2HY9 can be used to simulate quadruplexes with different topologies. The CG model was further applied to a higher order human telomeric quadruplex formed by the repetition, 20 times, of the 1KF1 quadruplex structure. In all cases, the developed model, which to the best of our knowledge is the first model of quadruplexes at the CG level presented in the literature, reproduces the main structural features remarkably well.
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Affiliation(s)
- Matúš Rebič
- Department of Biophysics, Faculty of Science, P. J. Šafárik University , Jesenná 5, 041 54 Košice, Slovakia
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Wei D, Husby J, Neidle S. Flexibility and structural conservation in a c-KIT G-quadruplex. Nucleic Acids Res 2014; 43:629-44. [PMID: 25452341 PMCID: PMC4288176 DOI: 10.1093/nar/gku1282] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A quadruplex sequence from the promoter region of the c-KIT gene forms a stable quadruplex, as characterized by crystallographic and NMR methods. Two new crystal structures are reported here, together with molecular dynamics simulation studies on these quadruplex crystal structures and an NMR structure. The new crystal structures, each in a distinct space group and lattice packing arrangement, together with the existing structures, demonstrate that the c-KIT quadruplex fold does not change with differing environments, suggesting that quadruplex topological dynamism is not a general phenomenon. The single and dinucleotide loops in these structures show a high degree of conformational flexibility within the three crystal forms and the NMR ensemble, with no evidence of clustering to particular conformers. This is in accord with the findings of high loop flexibility from the molecular dynamics studies. It is suggested that intramolecular quadruplexes can be grouped into two broad classes (i) those with at least one single-nucleotide loop, often showing singular topologies even though loops are highly flexible, and (ii) with all loops comprising at least two nucleotides, leading to topological dynamism. The loops can have more stable and less dynamic base-stacked secondary structures.
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Affiliation(s)
- Dengguo Wei
- UCL School of Pharmacy, University College London, London WC1N 1AX, UK
| | - Jarmila Husby
- UCL School of Pharmacy, University College London, London WC1N 1AX, UK
| | - Stephen Neidle
- UCL School of Pharmacy, University College London, London WC1N 1AX, UK
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50
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Triplex intermediates in folding of human telomeric quadruplexes probed by microsecond-scale molecular dynamics simulations. Biochimie 2014; 105:22-35. [DOI: 10.1016/j.biochi.2014.07.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 07/01/2014] [Indexed: 11/23/2022]
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