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Schroeder GM, Kiliushik D, Jenkins JL, Wedekind JE. Structure and function analysis of a type III preQ 1-I riboswitch from Escherichia coli reveals direct metabolite sensing by the Shine-Dalgarno sequence. J Biol Chem 2023; 299:105208. [PMID: 37660906 PMCID: PMC10622847 DOI: 10.1016/j.jbc.2023.105208] [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: 06/27/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/05/2023] Open
Abstract
Riboswitches are small noncoding RNAs found primarily in the 5' leader regions of bacterial messenger RNAs where they regulate expression of downstream genes in response to binding one or more cellular metabolites. Such noncoding RNAs are often regulated at the translation level, which is thought to be mediated by the accessibility of the Shine-Dalgarno sequence (SDS) ribosome-binding site. Three classes (I-III) of prequeuosine1 (preQ1)-sensing riboswitches are known that control translation. Class I is divided into three subtypes (types I-III) that have diverse mechanisms of sensing preQ1, which is involved in queuosine biosynthesis. To provide insight into translation control, we determined a 2.30 Å-resolution cocrystal structure of a class I type III preQ1-sensing riboswitch identified in Escherichia coli (Eco) by bioinformatic searches. The Eco riboswitch structure differs from previous preQ1 riboswitch structures because it has the smallest naturally occurring aptamer and the SDS directly contacts the preQ1 metabolite. We validated structural observations using surface plasmon resonance and in vivo gene-expression assays, which showed strong switching in live E. coli. Our results demonstrate that the Eco riboswitch is relatively sensitive to mutations that disrupt noncanonical interactions that form the pseudoknot. In contrast to type II preQ1 riboswitches, a kinetic analysis showed that the type III Eco riboswitch strongly prefers preQ1 over the chemically similar metabolic precursor preQ0. Our results reveal the importance of noncanonical interactions in riboswitch-driven gene regulation and the versatility of the class I preQ1 riboswitch pseudoknot as a metabolite-sensing platform that supports SDS sequestration.
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Affiliation(s)
- Griffin M Schroeder
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Daniil Kiliushik
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Jermaine L Jenkins
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Joseph E Wedekind
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
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2
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Schroeder GM, Akinyemi O, Malik J, Focht CM, Pritchett E, Baker C, McSally JP, Jenkins JL, Mathews D, Wedekind J. A riboswitch separated from its ribosome-binding site still regulates translation. Nucleic Acids Res 2023; 51:2464-2484. [PMID: 36762498 PMCID: PMC10018353 DOI: 10.1093/nar/gkad056] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/14/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Riboswitches regulate downstream gene expression by binding cellular metabolites. Regulation of translation initiation by riboswitches is posited to occur by metabolite-mediated sequestration of the Shine-Dalgarno sequence (SDS), causing bypass by the ribosome. Recently, we solved a co-crystal structure of a prequeuosine1-sensing riboswitch from Carnobacterium antarcticum that binds two metabolites in a single pocket. The structure revealed that the second nucleotide within the gene-regulatory SDS, G34, engages in a crystal contact, obscuring the molecular basis of gene regulation. Here, we report a co-crystal structure wherein C10 pairs with G34. However, molecular dynamics simulations reveal quick dissolution of the pair, which fails to reform. Functional and chemical probing assays inside live bacterial cells corroborate the dispensability of the C10-G34 pair in gene regulation, leading to the hypothesis that the compact pseudoknot fold is sufficient for translation attenuation. Remarkably, the C. antarcticum aptamer retained significant gene-regulatory activity when uncoupled from the SDS using unstructured spacers up to 10 nucleotides away from the riboswitch-akin to steric-blocking employed by sRNAs. Accordingly, our work reveals that the RNA fold regulates translation without SDS sequestration, expanding known riboswitch-mediated gene-regulatory mechanisms. The results infer that riboswitches exist wherein the SDS is not embedded inside a stable fold.
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Affiliation(s)
- Griffin M Schroeder
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Olayinka Akinyemi
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Department of Physics, University of Rochester, Rochester, NY 14642, USA
| | - Jeffrey Malik
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Caroline M Focht
- Department of Molecular Biophysics and Biochemistry and the Institute of Biomolecular Design and Discovery, Yale University, New Haven, CT 06516, USA
| | - Elizabeth M Pritchett
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Cameron D Baker
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - James P McSally
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Jermaine L Jenkins
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - David H Mathews
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Joseph E Wedekind
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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3
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Paloncýová M, Pykal M, Kührová P, Banáš P, Šponer J, Otyepka M. Computer Aided Development of Nucleic Acid Applications in Nanotechnologies. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2204408. [PMID: 36216589 DOI: 10.1002/smll.202204408] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Utilization of nucleic acids (NAs) in nanotechnologies and nanotechnology-related applications is a growing field with broad application potential, ranging from biosensing up to targeted cell delivery. Computer simulations are useful techniques that can aid design and speed up development in this field. This review focuses on computer simulations of hybrid nanomaterials composed of NAs and other components. Current state-of-the-art molecular dynamics simulations, empirical force fields (FFs), and coarse-grained approaches for the description of deoxyribonucleic acid and ribonucleic acid are critically discussed. Challenges in combining biomacromolecular and nanomaterial FFs are emphasized. Recent applications of simulations for modeling NAs and their interactions with nano- and biomaterials are overviewed in the fields of sensing applications, targeted delivery, and NA templated materials. Future perspectives of development are also highlighted.
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Affiliation(s)
- Markéta Paloncýová
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
| | - Martin Pykal
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
| | - Petra Kührová
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
| | - Pavel Banáš
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
| | - Jiří Šponer
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
- Institute of Biophysics of the Czech Academy of Sciences, v. v. i., Královopolská 135, Brno, 612 65, Czech Republic
| | - Michal Otyepka
- Regional Center of Advanced Technologies and Materials, The Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 779 00, Czech Republic
- IT4Innovations, VŠB - Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba, 708 00, Czech Republic
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4
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Zhou Y, Jiang Y, Chen SJ. RNA-ligand molecular docking: advances and challenges. WILEY INTERDISCIPLINARY REVIEWS. COMPUTATIONAL MOLECULAR SCIENCE 2022; 12:e1571. [PMID: 37293430 PMCID: PMC10250017 DOI: 10.1002/wcms.1571] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/20/2021] [Indexed: 12/16/2022]
Abstract
With rapid advances in computer algorithms and hardware, fast and accurate virtual screening has led to a drastic acceleration in selecting potent small molecules as drug candidates. Computational modeling of RNA-small molecule interactions has become an indispensable tool for RNA-targeted drug discovery. The current models for RNA-ligand binding have mainly focused on the docking-and-scoring method. Accurate docking and scoring should tackle four crucial problems: (1) conformational flexibility of ligand, (2) conformational flexibility of RNA, (3) efficient sampling of binding sites and binding poses, and (4) accurate scoring of different binding modes. Moreover, compared with the problem of protein-ligand docking, predicting ligand binding to RNA, a negatively charged polymer, is further complicated by additional effects such as metal ion effects. Thermodynamic models based on physics-based and knowledge-based scoring functions have shown highly encouraging success in predicting ligand binding poses and binding affinities. Recently, kinetic models for ligand binding have further suggested that including dissociation kinetics (residence time) in ligand docking would result in improved performance in estimating in vivo drug efficacy. More recently, the rise of deep-learning approaches has led to new tools for predicting RNA-small molecule binding. In this review, we present an overview of the recently developed computational methods for RNA-ligand docking and their advantages and disadvantages.
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Affiliation(s)
- Yuanzhe Zhou
- Department of Physics and Astronomy, Department of Biochemistry, Institute of Data Sciences and Informatics, University of Missouri, Columbia, MO 65211-7010, USA
| | - Yangwei Jiang
- Department of Physics and Astronomy, Department of Biochemistry, Institute of Data Sciences and Informatics, University of Missouri, Columbia, MO 65211-7010, USA
| | - Shi-Jie Chen
- Department of Physics and Astronomy, Department of Biochemistry, Institute of Data Sciences and Informatics, University of Missouri, Columbia, MO 65211-7010, USA
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5
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A small RNA that cooperatively senses two stacked metabolites in one pocket for gene control. Nat Commun 2022; 13:199. [PMID: 35017488 PMCID: PMC8752633 DOI: 10.1038/s41467-021-27790-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022] Open
Abstract
Riboswitches are structured non-coding RNAs often located upstream of essential genes in bacterial messenger RNAs. Such RNAs regulate expression of downstream genes by recognizing a specific cellular effector. Although nearly 50 riboswitch classes are known, only a handful recognize multiple effectors. Here, we report the 2.60-Å resolution co-crystal structure of a class I type I preQ1-sensing riboswitch that reveals two effectors stacked atop one another in a single binding pocket. These effectors bind with positive cooperativity in vitro and both molecules are necessary for gene regulation in bacterial cells. Stacked effector recognition appears to be a hallmark of the largest subgroup of preQ1 riboswitches, including those from pathogens such as Neisseria gonorrhoeae. We postulate that binding to stacked effectors arose in the RNA World to closely position two substrates for RNA-mediated catalysis. These findings expand known effector recognition capabilities of riboswitches and have implications for antimicrobial development. Riboswitches contain an aptamer domain that recognizes a metabolite and an expression platform that regulates gene expression. Here the authors report the crystal structure of a preQ1-sensing riboswitch from Carnobacterium antarcticus that shows two metabolites in a single binding pocket.
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6
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Manigrasso J, Marcia M, De Vivo M. Computer-aided design of RNA-targeted small molecules: A growing need in drug discovery. Chem 2021. [DOI: 10.1016/j.chempr.2021.05.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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7
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Negi I, Mahmi AS, Seelam Prabhakar P, Sharma P. Molecular Dynamics Simulations of the Aptamer Domain of Guanidinium Ion Binding Riboswitch ykkC-III: Structural Insights into the Discrimination of Cognate and Alternate Ligands. J Chem Inf Model 2021; 61:5243-5255. [PMID: 34609872 DOI: 10.1021/acs.jcim.1c01022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Guanidinium ion is a toxic cellular metabolite. The ykkC-III riboswitch, an mRNA stretch, regulates the gene expression by undergoing a conformational change in response to the binding of a free guanidinium ion and thereby plays a potentially important role in alleviating guanidinium toxicity in cells. An experimental crystal structure of the guanidinium-bound aptamer domain of the riboswitch from Thermobifida Fusca revealed the overall RNA architecture and mapped the specific noncovalent interactions that stabilize the ligand within the binding pocket aptamer. However, details of how the aptamer domain discriminates the cognate ligand from its closest structurally analogous physiological metabolites (arginine and urea), and how the binding of cognate ligand arrays information from the aptamer domain to the expression platform for regulating the gene expression, are not well understood. To fill this void, we perform a cumulative of 2 μs all-atom explicit-solvent molecular dynamics (MD) simulations on the full aptamer domain, augmented with quantum-chemical calculations on the ligand-binding pocket, to compare the structural and dynamical details of the guanidinium-bound state with the arginine or urea bound states, as well as the unbound (open) state. Analysis of the ligand-binding pocket reveals that due to unfavorable interactions with the binding-pocket residues, urea cannot bind the aptamer domain and thereby cannot alter the gene expression. Although interaction of the guanidyl moiety of arginine within the binding pocket is either comparable or stronger than the guanidinium ion, additional non-native hydrogen-bonding networks, as well as differences in the dynamical details of the arginine-bound state, explain why arginine cannot transmit the information from the aptamer domain to the expression platform. Based on our simulations, we propose a mechanism of how the aptamer domain communicates with the expression platform. Overall, our work provides interesting insights into the ligand recognition by a specific class of riboswitches and may hopefully inspire future studies to further understand the gene regulation by riboswitches.
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Affiliation(s)
- Indu Negi
- Computational Biochemistry Laboratory, Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
| | - Amanpreet Singh Mahmi
- Computational Biochemistry Laboratory, Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
| | - Preethi Seelam Prabhakar
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad, Telangana 500032, India
| | - Purshotam Sharma
- Computational Biochemistry Laboratory, Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
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8
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Schlick T, Portillo-Ledesma S, Myers CG, Beljak L, Chen J, Dakhel S, Darling D, Ghosh S, Hall J, Jan M, Liang E, Saju S, Vohr M, Wu C, Xu Y, Xue E. Biomolecular Modeling and Simulation: A Prospering Multidisciplinary Field. Annu Rev Biophys 2021; 50:267-301. [PMID: 33606945 PMCID: PMC8105287 DOI: 10.1146/annurev-biophys-091720-102019] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We reassess progress in the field of biomolecular modeling and simulation, following up on our perspective published in 2011. By reviewing metrics for the field's productivity and providing examples of success, we underscore the productive phase of the field, whose short-term expectations were overestimated and long-term effects underestimated. Such successes include prediction of structures and mechanisms; generation of new insights into biomolecular activity; and thriving collaborations between modeling and experimentation, including experiments driven by modeling. We also discuss the impact of field exercises and web games on the field's progress. Overall, we note tremendous success by the biomolecular modeling community in utilization of computer power; improvement in force fields; and development and application of new algorithms, notably machine learning and artificial intelligence. The combined advances are enhancing the accuracy andscope of modeling and simulation, establishing an exemplary discipline where experiment and theory or simulations are full partners.
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Affiliation(s)
- Tamar Schlick
- Department of Chemistry, New York University, New York, New York 10003, USA;
- Courant Institute of Mathematical Sciences, New York University, New York, New York 10012, USA
- New York University-East China Normal University Center for Computational Chemistry, New York University Shanghai, Shanghai 200122, China
| | | | - Christopher G Myers
- Department of Chemistry, New York University, New York, New York 10003, USA;
| | - Lauren Beljak
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Justin Chen
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Sami Dakhel
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Daniel Darling
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Sayak Ghosh
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Joseph Hall
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Mikaeel Jan
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Emily Liang
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Sera Saju
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Mackenzie Vohr
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Chris Wu
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Yifan Xu
- College of Arts and Science, New York University, New York, New York 10003, USA
| | - Eva Xue
- College of Arts and Science, New York University, New York, New York 10003, USA
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9
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Schroeder GM, Dutta D, Cavender CE, Jenkins J, Pritchett EM, Baker CD, Ashton JM, Mathews DH, Wedekind JE. Analysis of a preQ1-I riboswitch in effector-free and bound states reveals a metabolite-programmed nucleobase-stacking spine that controls gene regulation. Nucleic Acids Res 2020; 48:8146-8164. [PMID: 32597951 PMCID: PMC7641330 DOI: 10.1093/nar/gkaa546] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/13/2020] [Accepted: 06/16/2020] [Indexed: 01/20/2023] Open
Abstract
Riboswitches are structured RNA motifs that recognize metabolites to alter the conformations of downstream sequences, leading to gene regulation. To investigate this molecular framework, we determined crystal structures of a preQ1-I riboswitch in effector-free and bound states at 2.00 Å and 2.65 Å-resolution. Both pseudoknots exhibited the elusive L2 loop, which displayed distinct conformations. Conversely, the Shine-Dalgarno sequence (SDS) in the S2 helix of each structure remained unbroken. The expectation that the effector-free state should expose the SDS prompted us to conduct solution experiments to delineate environmental changes to specific nucleobases in response to preQ1. We then used nudged elastic band computational methods to derive conformational-change pathways linking the crystallographically-determined effector-free and bound-state structures. Pathways featured: (i) unstacking and unpairing of L2 and S2 nucleobases without preQ1-exposing the SDS for translation and (ii) stacking and pairing L2 and S2 nucleobases with preQ1-sequestering the SDS. Our results reveal how preQ1 binding reorganizes L2 into a nucleobase-stacking spine that sequesters the SDS, linking effector recognition to biological function. The generality of stacking spines as conduits for effector-dependent, interdomain communication is discussed in light of their existence in adenine riboswitches, as well as the turnip yellow mosaic virus ribosome sensor.
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Affiliation(s)
- Griffin M Schroeder
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Debapratim Dutta
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Chapin E Cavender
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Jermaine L Jenkins
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Elizabeth M Pritchett
- Genomics Research Center, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Cameron D Baker
- Genomics Research Center, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - John M Ashton
- Genomics Research Center, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
| | - Joseph E Wedekind
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642, USA
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10
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Li C, Zhao X, Zhu X, Xie P, Chen G. Structural Studies of the 3',3'-cGAMP Riboswitch Induced by Cognate and Noncognate Ligands Using Molecular Dynamics Simulation. Int J Mol Sci 2018; 19:ijms19113527. [PMID: 30423927 PMCID: PMC6274999 DOI: 10.3390/ijms19113527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/03/2018] [Accepted: 11/04/2018] [Indexed: 01/09/2023] Open
Abstract
Riboswtich RNAs can control gene expression through the structural change induced by the corresponding small-molecule ligands. Molecular dynamics simulations and free energy calculations on the aptamer domain of the 3′,3′-cGAMP riboswitch in the ligand-free, cognate-bound and noncognate-bound states were performed to investigate the structural features of the 3′,3′-cGAMP riboswitch induced by the 3′,3′-cGAMP ligand and the specificity of ligand recognition. The results revealed that the aptamer of the 3′,3′-cGAMP riboswitch in the ligand-free state has a smaller binding pocket and a relatively compact structure versus that in the 3′,3′-cGAMP-bound state. The binding of the 3′,3′-cGAMP molecule to the 3′,3′-cGAMP riboswitch induces the rotation of P1 helix through the allosteric communication from the binding sites pocket containing the J1/2, J1/3 and J2/3 junction to the P1 helix. Simultaneously, these simulations also revealed that the preferential binding of the 3′,3′-cGAMP riboswitch to its cognate ligand, 3′,3′-cGAMP, over its noncognate ligand, c-di-GMP and c-di-AMP. The J1/2 junction in the 3′,3′-cGAMP riboswitch contributing to the specificity of ligand recognition have also been found.
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Affiliation(s)
- Chaoqun Li
- College of Chemistry, Chemical Engineering and Materials, Handan University, No. 530 North Xueyuan Road, Hanshan District, Han Dan 056005, Hebei, China.
| | - Xiaojia Zhao
- College of Chemistry, Chemical Engineering and Materials, Handan University, No. 530 North Xueyuan Road, Hanshan District, Han Dan 056005, Hebei, China.
| | - Xiaomin Zhu
- College of Chemistry, Chemical Engineering and Materials, Handan University, No. 530 North Xueyuan Road, Hanshan District, Han Dan 056005, Hebei, China.
| | - Pengtao Xie
- College of Chemistry, Chemical Engineering and Materials, Handan University, No. 530 North Xueyuan Road, Hanshan District, Han Dan 056005, Hebei, China.
| | - Guangju Chen
- College of Chemistry, Beijing Normal University, 19# Xinjiekouwai Street, Beijing 100875, China.
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11
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Kesherwani M, N H V K, Velmurugan D. Conformational Dynamics of thiM Riboswitch To Understand the Gene Regulation Mechanism Using Markov State Modeling and the Residual Fluctuation Network Approach. J Chem Inf Model 2018; 58:1638-1651. [PMID: 29939019 DOI: 10.1021/acs.jcim.8b00155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Thiamine pyrophosphate (TPP) riboswitch is a cis-regulatory element in the noncoding region of mRNA. The aptamer domain of TPP riboswitch detects the high abundance of coenzyme thiamine pyrophosphate (TPP) and modulates the gene expression for thiamine synthetic gene. The mechanistic understanding in recognition of TPP in aptamer domain and ligand-induced compactness for folding of expression platform are most important to designing novel modulators. To understand the dynamic behavior of TPP riboswitch upon TPP binding, molecular dynamics simulations were performed for 400 ns in both apo and TPP bound forms of thiM riboswitch from E. coli and analyzed in terms of eRMSD-based Markov state modeling and residual fluctuation network. Markov state models show good correlations in transition probability among metastable states from simulated trajectory and generated models. Structural compactness in TPP bound form is observed which is correlated with SAXS experiment. The importance of junction of P4 and P5 is evident during dynamics, which correlates with FRET analysis. The dynamic nature of two sensor forearms is due to the flexible P1 helix, which is its intrinsic property. The transient state in TPP-bound form was observed in the Markov state model, along with stable states. We believe that this transient state is responsible to assist the influx and outflux of ligand molecule by creating a solvent channel around the junction region of P4 and P5 and such a structure was anticipated in FRET analysis. The dynamic nature of riboswitch is dependent on the interaction between residues on distal loops L3 and L5/P3 and junction P4 and P5, J3/2 which stabilize the J2/4. It helps in the transfer of allosteric information between J2/4 and P3/L5 tertiary docking region through the active site residues. Understanding such information flow will benefit in highlighting crucial residues in highly dynamic and kinetic systems. Here, we report the residues and segments in riboswitch that play vital roles in providing stability and this can be exploited in designing inhibitors to regulate the functioning of riboswitches.
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Affiliation(s)
- Manish Kesherwani
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
| | - Kutumbarao N H V
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
| | - Devadasan Velmurugan
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
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12
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Li C, Zhao X, Xie P, Hu J, Bi H. Molecular dynamics simulation on the allosteric analysis of the c-di-GMP class I riboswitch induced by ligand binding. J Mol Recognit 2018; 32:e2756. [PMID: 30033590 DOI: 10.1002/jmr.2756] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 02/02/2023]
Abstract
Riboswitches are RNA molecules that regulate gene expression using conformation change, affected by binding of small molecule ligands. Although a number of ligand-bound aptamer complex structures have been solved, it is important to know ligand-free conformations of the aptamers in order to understand the mechanism of specific binding by ligands. In this paper, we use dynamics simulations on a series of models to characterize the ligand-free and ligand-bound aptamer domain of the c-di-GMP class I (GEMM-I) riboswitch. The results revealed that the ligand-free aptamer has a stable state with a folded P2 and P3 helix, an unfolded P1 helix and open binding pocket. The first Mg ions binding to the aptamer is structurally favorable for the successive c-di-GMP binding. The P1 helix forms when c-di-GMP is successive bound. Three key junctions J1/2, J2/3 and J1/3 in the GEMM-I riboswitch contributing to the formation of P1 helix have been found. The binding of the c-di-GMP ligand to the GEMM-I riboswitch induces the riboswitch's regulation through the direct allosteric communication network in GEMM-I riboswitch from the c-di-GMP binding sites in the J1/2 and J1/3 junctions to the P1 helix, the indirect ones from those in the J2/3 and P2 communicating to P1 helix via the J1/2 and J1/3 media.
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Affiliation(s)
- Chaoqun Li
- College of Chemistry, Chemical Engineering and Materials, Handan University, No.530 North Xueyuan Road, Hanshan District, Han Dan, Hebei province, China
| | - Xiaojia Zhao
- College of Chemistry, Chemical Engineering and Materials, Handan University, No.530 North Xueyuan Road, Hanshan District, Han Dan, Hebei province, China
| | - Pengtao Xie
- College of Chemistry, Chemical Engineering and Materials, Handan University, No.530 North Xueyuan Road, Hanshan District, Han Dan, Hebei province, China
| | - Junping Hu
- College of Chemistry, Chemical Engineering and Materials, Handan University, No.530 North Xueyuan Road, Hanshan District, Han Dan, Hebei province, China
| | - Huimin Bi
- College of Chemistry, Chemical Engineering and Materials, Handan University, No.530 North Xueyuan Road, Hanshan District, Han Dan, Hebei province, China
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13
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Šponer J, Bussi G, Krepl M, Banáš P, Bottaro S, Cunha RA, Gil-Ley A, Pinamonti G, Poblete S, Jurečka P, Walter NG, Otyepka M. RNA Structural Dynamics As Captured by Molecular Simulations: A Comprehensive Overview. Chem Rev 2018; 118:4177-4338. [PMID: 29297679 PMCID: PMC5920944 DOI: 10.1021/acs.chemrev.7b00427] [Citation(s) in RCA: 336] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Indexed: 12/14/2022]
Abstract
With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Department of Biology , University of Copenhagen , Copenhagen 2200 , Denmark
| | - Richard A Cunha
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Giovanni Pinamonti
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Simón Poblete
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
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14
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Šponer JE, Szabla R, Góra RW, Saitta AM, Pietrucci F, Saija F, Di Mauro E, Saladino R, Ferus M, Civiš S, Šponer J. Prebiotic synthesis of nucleic acids and their building blocks at the atomic level - merging models and mechanisms from advanced computations and experiments. Phys Chem Chem Phys 2018; 18:20047-66. [PMID: 27136968 DOI: 10.1039/c6cp00670a] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The origin of life on Earth is one of the most fascinating questions of contemporary science. Extensive research in the past decades furnished diverse experimental proposals for the emergence of first informational polymers that could form the basis of the early terrestrial life. Side by side with the experiments, the fast development of modern computational chemistry methods during the last 20 years facilitated the use of in silico modelling tools to complement the experiments. Modern computations can provide unique atomic-level insights into the structural and electronic aspects as well as the energetics of key prebiotic chemical reactions. Many of these insights are not directly obtainable from the experimental techniques and the computations are thus becoming indispensable for proper interpretation of many experiments and for qualified predictions. This review illustrates the synergy between experiment and theory in the origin of life research focusing on the prebiotic synthesis of various nucleic acid building blocks and on the self-assembly of nucleotides leading to the first functional oligonucleotides.
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Affiliation(s)
- Judit E Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic. and CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Rafał Szabla
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic.
| | - Robert W Góra
- Theoretical Chemistry Group, Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - A Marco Saitta
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, UMR 7590, F-75005 Paris, France
| | - Fabio Pietrucci
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, UMR 7590, F-75005 Paris, France
| | - Franz Saija
- CNR-IPCF, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina, Italy
| | - Ernesto Di Mauro
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", "Sapienza" Università di Roma, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Raffaele Saladino
- Dipartimento di Scienze Ecologiche e Biologiche Università della Tuscia, Via San Camillo De Lellis, 01100 Viterbo, Italy
| | - Martin Ferus
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague 8, Czech Republic
| | - Svatopluk Civiš
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague 8, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic. and CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
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15
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Hanke CA, Gohlke H. Tertiary Interactions in the Unbound Guanine-Sensing Riboswitch Focus Functional Conformational Variability on the Binding Site. J Chem Inf Model 2017; 57:2822-2832. [DOI: 10.1021/acs.jcim.7b00567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Christian A. Hanke
- Mathematisch-Naturwissenschaftliche
Fakultät, Institut für Pharmazeutische und Medizinische
Chemie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Holger Gohlke
- Mathematisch-Naturwissenschaftliche
Fakultät, Institut für Pharmazeutische und Medizinische
Chemie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC) & Institute for Complex Systems - Structural Biochemistry (ICS 6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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16
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Choi YJ, Gibala KS, Ayele T, Deventer KV, Resendiz MJE. Biophysical properties, thermal stability and functional impact of 8-oxo-7,8-dihydroguanine on oligonucleotides of RNA-a study of duplex, hairpins and the aptamer for preQ1 as models. Nucleic Acids Res 2017; 45:2099-2111. [PMID: 28426093 PMCID: PMC5389535 DOI: 10.1093/nar/gkw885] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/22/2016] [Indexed: 01/12/2023] Open
Abstract
A better understanding of the effects that oxidative lesions have on RNA is of importance to understand their role in the development/progression of disease. 8-oxo-7,8-dihydroguanine was incorporated into RNA to understand its structural and functional impact on RNA:RNA and RNA:DNA duplexes, hairpins and pseudoknots. One to three modifications were incorporated into dodecamers of RNA [AAGAGGGAUGAC] resulting in thermal destabilization (ΔTm – 10°C per lesion). Hairpins with tetraloops c-UUCG*-g* (8-10), a-ACCG-g* (11-12), c-UUG*G*-g* (13-16) and c-ACG*G*-g* (17-20) were modified and used to determine thermal stabilities, concluding that: (i) modifying the stem leads to destabilization unless adenosine is the opposing basepair of 8-oxoGua; (ii) modification at the loop is position- and sequence-dependent and varies from slight stabilization to large destabilization, in some cases leading to formation of other secondary structures (hairpin→duplex). Functional effects were established using the aptamer for preQ1 as model. Modification at G5 disrupted the stem P1 and inhibited recognition of the target molecule 7-methylamino-7-deazaguanine (preQ1). Modifying G11 results in increased thermal stability, albeit with a Kd 4-fold larger than its canonical analog. These studies show the capability of 8-oxoG to affect structure and function of RNA, resulting in distinct outcomes as a function of number and position of the lesion.
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Affiliation(s)
- Yu J Choi
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Krzysztof S Gibala
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Tewoderos Ayele
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Katherine V Deventer
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Marino J E Resendiz
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
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17
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Hanke CA, Gohlke H. Ligand-mediated and tertiary interactions cooperatively stabilize the P1 region in the guanine-sensing riboswitch. PLoS One 2017; 12:e0179271. [PMID: 28640851 PMCID: PMC5480868 DOI: 10.1371/journal.pone.0179271] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 05/27/2017] [Indexed: 12/18/2022] Open
Abstract
Riboswitches are genetic regulatory elements that control gene expression depending on ligand binding. The guanine-sensing riboswitch (Gsw) binds ligands at a three-way junction formed by paired regions P1, P2, and P3. Loops L2 and L3 cap the P2 and P3 helices and form tertiary interactions. Part of P1 belongs to the switching sequence dictating the fate of the mRNA. Previous studies revealed an intricate relationship between ligand binding and presence of the tertiary interactions, and between ligand binding and influence on the P1 region. However, no information is available on the interplay among these three main regions in Gsw. Here we show that stabilization of the L2-L3 region by tertiary interactions, and the ligand binding site by ligand binding, cooperatively influences the structural stability of terminal base pairs in the P1 region in the presence of Mg2+ ions. The results are based on molecular dynamics simulations with an aggregate simulation time of ~10 μs across multiple systems of the unbound state of the Gsw aptamer and a G37A/C61U mutant, and rigidity analyses. The results could explain why the three-way junction is a central structural element also in other riboswitches and how the cooperative effect could become contextual with respect to intracellular Mg2+ concentration. The results suggest that the transmission of allosteric information to P1 can be entropy-dominated.
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Affiliation(s)
- Christian A. Hanke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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18
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Zgarbová M, Jurečka P, Banáš P, Havrila M, Šponer J, Otyepka M. Noncanonical α/γ Backbone Conformations in RNA and the Accuracy of Their Description by the AMBER Force Field. J Phys Chem B 2017; 121:2420-2433. [PMID: 28290207 DOI: 10.1021/acs.jpcb.7b00262] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The sugar-phosphate backbone of RNA can exist in diverse rotameric substates, giving RNA molecules enormous conformational variability. The most frequent noncanonical backbone conformation in RNA is α/γ = t/t, which is derived from the canonical backbone by a crankshaft motion and largely preserves the standard geometry of the RNA duplex. A similar conformation also exists in DNA, where it has been extensively studied and shown to be involved in DNA-protein interactions. However, the function of the α/γ = t/t conformation in RNA is poorly understood. Here, we present molecular dynamics simulations of several prototypical RNA structures obtained from X-ray and NMR experiments, including canonical and mismatched RNA duplexes, UUCG and GAGA tetraloops, Loop E, the sarcin-ricin loop, a parallel guanine quadruplex, and a viral pseudoknot. The stability of various noncanonical α/γ backbone conformations was analyzed with two AMBER force fields, ff99bsc0χOL3 and ff99bsc0χOL3 with the recent εζOL1 and βOL1 corrections for DNA. Although some α/γ substates were stable with seemingly well-described equilibria, many were unstable in our simulations. Notably, the most frequent noncanonical conformer α/γ = t/t was unstable in both tested force fields. Possible reasons for this instability are discussed. Our work reveals a potentially important artifact in RNA force fields and highlights a need for further force field refinement.
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Affiliation(s)
- Marie Zgarbová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Marek Havrila
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Jiří Šponer
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic.,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, 77146 Olomouc, Czech Republic
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19
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Šponer J, Krepl M, Banáš P, Kührová P, Zgarbová M, Jurečka P, Havrila M, Otyepka M. How to understand atomistic molecular dynamics simulations of RNA and protein-RNA complexes? WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27863061 DOI: 10.1002/wrna.1405] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/13/2016] [Accepted: 10/10/2016] [Indexed: 01/01/2023]
Abstract
We provide a critical assessment of explicit-solvent atomistic molecular dynamics (MD) simulations of RNA and protein/RNA complexes, written primarily for non-specialists with an emphasis to explain the limitations of MD. MD simulations can be likened to hypothetical single-molecule experiments starting from single atomistic conformations and investigating genuine thermal sampling of the biomolecules. The main advantage of MD is the unlimited temporal and spatial resolution of positions of all atoms in the simulated systems. Fundamental limitations are the short physical time-scale of simulations, which can be partially alleviated by enhanced-sampling techniques, and the highly approximate atomistic force fields describing the simulated molecules. The applicability and present limitations of MD are demonstrated on studies of tetranucleotides, tetraloops, ribozymes, riboswitches and protein/RNA complexes. Wisely applied simulations respecting the approximations of the model can successfully complement structural and biochemical experiments. WIREs RNA 2017, 8:e1405. doi: 10.1002/wrna.1405 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Marie Zgarbová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Marek Havrila
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
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20
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Kührová P, Best RB, Bottaro S, Bussi G, Šponer J, Otyepka M, Banáš P. Computer Folding of RNA Tetraloops: Identification of Key Force Field Deficiencies. J Chem Theory Comput 2016; 12:4534-48. [PMID: 27438572 PMCID: PMC6169534 DOI: 10.1021/acs.jctc.6b00300] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The computer-aided folding of biomolecules, particularly RNAs, is one of the most difficult challenges in computational structural biology. RNA tetraloops are fundamental RNA motifs playing key roles in RNA folding and RNA-RNA and RNA-protein interactions. Although state-of-the-art Molecular Dynamics (MD) force fields correctly describe the native state of these tetraloops as a stable free-energy basin on the microsecond time scale, enhanced sampling techniques reveal that the native state is not the global free energy minimum, suggesting yet unidentified significant imbalances in the force fields. Here, we tested our ability to fold the RNA tetraloops in various force fields and simulation settings. We employed three different enhanced sampling techniques, namely, temperature replica exchange MD (T-REMD), replica exchange with solute tempering (REST2), and well-tempered metadynamics (WT-MetaD). We aimed to separate problems caused by limited sampling from those due to force-field inaccuracies. We found that none of the contemporary force fields is able to correctly describe folding of the 5'-GAGA-3' tetraloop over a range of simulation conditions. We thus aimed to identify which terms of the force field are responsible for this poor description of TL folding. We showed that at least two different imbalances contribute to this behavior, namely, overstabilization of base-phosphate and/or sugar-phosphate interactions and underestimated stability of the hydrogen bonding interaction in base pairing. The first artifact stabilizes the unfolded ensemble, while the second one destabilizes the folded state. The former problem might be partially alleviated by reparametrization of the van der Waals parameters of the phosphate oxygens suggested by Case et al., while in order to overcome the latter effect we suggest local potentials to better capture hydrogen bonding interactions.
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Affiliation(s)
- 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,
| | - Robert B. Best
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520
| | - Sandro Bottaro
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Jiří Šponer
- 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,
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - 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,
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, 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,
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
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21
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Suresh G, Srinivasan H, Nanda S, Priyakumar UD. Ligand-Induced Stabilization of a Duplex-like Architecture Is Crucial for the Switching Mechanism of the SAM-III Riboswitch. Biochemistry 2016; 55:3349-60. [PMID: 27249101 DOI: 10.1021/acs.biochem.5b00973] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Riboswitches are structured RNA motifs that control gene expression by sensing the concentrations of specific metabolites and make up a promising new class of antibiotic targets. S-Adenosylmethionine (SAM)-III riboswitch, mainly found in lactic acid bacteria, is involved in regulating methionine and SAM biosynthetic pathways. SAM-III riboswitch regulates the gene expression by switching the translation process on and off with respect to the absence and presence of the SAM ligand, respectively. In this study, an attempt is made to understand the key conformational transitions involved in ligand binding using atomistic molecular dynamics (MD) simulations performed in an explicit solvent environment. G26 is found to recognize the SAM ligand by forming hydrogen bonds, whereas the absence of the ligand leads to opening of the binding pocket. Consistent with experimental results, the absence of the SAM ligand weakens the base pairing interactions between the nucleobases that are part of the Shine-Dalgarno (SD) and anti-Shine-Dalgarno (aSD) sequences, which in turn facilitates recognition of the SD sequence by ribosomes. Detailed analysis reveals that a duplex-like structure formed by nucleotides from different parts of the RNA and the adenine base of the ligand is crucial for the stability of the completely folded state in the presence of the ligand. Previous experimental studies have shown that the SAM-III riboswitch exists in equilibrium between the unfolded and partially folded states in the absence of the ligand, which completely folds upon binding of the ligand. Comparison of the results presented here to the available experimental data indicates the structures obtained using the MD simulations resemble the partially folded state. Thus, this study provides a detailed understanding of the fully and partially folded structures of the SAM-III riboswitch in the presence and absence of the ligand, respectively. This study hypothesizes a dual role for the SAM ligand, which facilitates conformational switching between partially and fully folded states by forming a stable duplex-like structure and strengthening the interactions between SD and aSD nucleotides.
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Affiliation(s)
- Gorle Suresh
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology , Hyderabad 500 032, India
| | - Harini Srinivasan
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology , Hyderabad 500 032, India
| | - Shivani Nanda
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology , Hyderabad 500 032, India
| | - U Deva Priyakumar
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology , Hyderabad 500 032, India
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22
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Frener M, Micura R. Conformational Rearrangements of Individual Nucleotides during RNA-Ligand Binding Are Rate-Differentiated. J Am Chem Soc 2016; 138:3627-30. [PMID: 26974261 PMCID: PMC4959565 DOI: 10.1021/jacs.5b11876] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A pronounced rate differentiation has been found for conformational rearrangements of individual nucleobases that occur during ligand recognition of the preQ1 class-I riboswitch aptamer from Thermoanaerobacter tengcongensis. Rate measurements rely on the 2ApFold approach by analyzing the fluorescence response of riboswitch variants, each with a single, strategically positioned 2-aminopurine nucleobase substitution. Observed rate discrimination between the fastest and the slowest conformational adaption is 22-fold, with the largest rate observed for the rearrangement of a nucleoside directly at the binding site and the smallest rate observed for the 3'-unpaired nucleoside that stacks onto the pseudo-knot-closing Watson-Crick base pair. Our findings provide novel insights into how compact, prefolded RNAs that follow the induced-fit recognition mechanism adapt local structural elements in response to ligand binding on a rather broad time scale and how this process culminates in a structural signal that is responsible for efficient downregulation of ribosomal translation.
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Affiliation(s)
- Marina Frener
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
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23
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Kührová P, Otyepka M, Šponer J, Banáš P. Are Waters around RNA More than Just a Solvent? - An Insight from Molecular Dynamics Simulations. J Chem Theory Comput 2015; 10:401-11. [PMID: 26579919 DOI: 10.1021/ct400663s] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Hydrating water molecules are believed to be an inherent part of the RNA structure and have a considerable impact on RNA conformation. However, the magnitude and mechanism of the interplay between water molecules and the RNA structure are still poorly understood. In principle, such hydration effects can be studied by molecular dynamics (MD) simulations. In our recent MD studies, we observed that the choice of water model has a visible impact on the predicted structure and structural dynamics of RNA and, in particular, has a larger effect than type, parametrization, and concentration of the ions. Furthermore, the water model effect is sequence dependent and modulates the sequence dependence of A-RNA helical parameters. Clearly, the sensitivity of A-RNA structural dynamics to the water model parametrization is a rather spurious effect that complicates MD studies of RNA molecules. These results nevertheless suggest that the sequence dependence of the A-RNA structure, usually attributed to base stacking, might be driven by the structural dynamics of specific hydration. Here, we present a systematic MD study that aimed to (i) clarify the atomistic mechanism of the water model sensitivity and (ii) discover whether and to what extent specific hydration modulates the A-RNA structural variability. We carried out an extended set of MD simulations of canonical A-RNA duplexes with TIP3P, TIP4P/2005, TIP5P, and SPC/E explicit water models and found that different water models provided a different extent of water bridging between 2'-OH groups across the minor groove, which in turn influences their distance and consequently also inclination, roll, and slide parameters. Minor groove hydration is also responsible for the sequence dependence of these helical parameters. Our simulations suggest that TIP5P is not optimal for RNA simulations.
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Affiliation(s)
- Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic.,Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic.,CEITEC - Central European Institute of Technology , Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , tr. 17. Listopadu 12, 771 46, Olomouc, Czech Republic.,Institute of Biophysics, Academy of Sciences of the Czech Republic , Kralovopolska 135, 612 65 Brno, Czech Republic
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24
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Schrodt MV, Andrews CT, Elcock AH. Large-Scale Analysis of 48 DNA and 48 RNA Tetranucleotides Studied by 1 μs Explicit-Solvent Molecular Dynamics Simulations. J Chem Theory Comput 2015; 11:5906-17. [PMID: 26580891 PMCID: PMC4806854 DOI: 10.1021/acs.jctc.5b00899] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An understanding of how the conformational behavior of single-stranded DNAs and RNAs depend on sequence is likely to be important for attempts to rationalize the thermodynamics of nucleic acid folding. In an attempt to further our understanding of such sequence dependences, we report here the results of 192 (1 μs) explicit-solvent molecular dynamics (MD) simulations of 48 DNA and 48 RNA tetranucleotide sequences performed using recently reported modifications to the AMBER force field. Each tetranucleotide was simulated starting from two different conformations, a fully natively stacked and a completely unstacked conformation, and populations of the various possible base stacking arrangements were analyzed. The simulations indicate that, for both DNA and RNA, the populations of fully natively stacked conformations increase linearly with increasing numbers of purines in the sequence, while the conformational entropies, computed by two complementary methods, decrease. Despite the comparatively short simulation times, the computed free energies of stacking of the 16 possible combinations of bases in the middle of the sequences are found to be in good correspondence with values reported recently from simulations of dinucleoside monophosphates using the same force field. Finally, consistent with recent reports from other groups, non-native stacking interactions, i.e., between bases that are not adjacent in sequence, are shown to be a recurring feature of the simulations; in particular, stacking interactions of bases in a i:i+2 relationship are shown to occur significantly more frequently when the intervening base is a pyrimidine. Given that the high prevalence of non-native stacking interactions is thought to be unrealistic, it appears that further parametrization work will be required before accurate conformational descriptions of single-stranded nucleic acids can be obtained with current force fields.
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Affiliation(s)
| | - Casey T. Andrews
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | - Adrian H. Elcock
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
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25
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Aytenfisu AH, Liberman JA, Wedekind JE, Mathews DH. Molecular mechanism for preQ1-II riboswitch function revealed by molecular dynamics. RNA (NEW YORK, N.Y.) 2015; 21:1898-907. [PMID: 26370581 PMCID: PMC4604430 DOI: 10.1261/rna.051367.115] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/02/2015] [Indexed: 05/06/2023]
Abstract
Riboswitches are RNA molecules that regulate gene expression using conformational change, affected by binding of small molecule ligands. A crystal structure of a ligand-bound class II preQ1 riboswitch has been determined in a previous structural study. To gain insight into the dynamics of this riboswitch in solution, eight total molecular dynamic simulations, four with and four without ligand, were performed using the Amber force field. In the presence of ligand, all four of the simulations demonstrated rearranged base pairs at the 3' end, consistent with expected base-pairing from comparative sequence analysis in a prior bioinformatic analysis; this suggests the pairing in this region was altered by crystallization. Additionally, in the absence of ligand, three of the simulations demonstrated similar changes in base-pairing at the ligand binding site. Significantly, although most of the riboswitch architecture remained intact in the respective trajectories, the P3 stem was destabilized in the ligand-free simulations in a way that exposed the Shine-Dalgarno sequence. This work illustrates how destabilization of two major groove base triples can influence a nearby H-type pseudoknot and provides a mechanism for control of gene expression by a fold that is frequently found in bacterial riboswitches.
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Affiliation(s)
- Asaminew H Aytenfisu
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Joseph A Liberman
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Joseph E Wedekind
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester Medical Center, Rochester, New York 14642, USA Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, New York 14642, USA
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26
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Bochicchio A, Rossetti G, Tabarrini O, Krauβ S, Carloni P. Molecular view of ligands specificity for CAG repeats in anti-Huntington therapy. J Chem Theory Comput 2015; 11:4911-22. [PMID: 26574279 DOI: 10.1021/acs.jctc.5b00208] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Huntington's disease is a fatal and devastating neurodegenerative genetic disorder for which there is currently no cure. It is characterized by Huntingtin protein's mRNA transcripts with 36 or more CAG repeats. Inhibiting the formation of pathological complexes between these expanded transcripts and target proteins may be a valuable strategy against the disease. Yet, the rational design of molecules specifically targeting the expanded CAG repeats is limited by the lack of structural information. Here, we use well-tempered metadynamics-based free energy calculations to investigate pose and affinity of two ligands targeting CAG repeats for which affinities have been previously measured. The first consists of two 4-guanidinophenyl rings linked by an ester group. It is the most potent ligand identified so far, with Kd = 60(30) nM. The second consists of a 4-phenyl dihydroimidazole and 4-1H-indole dihydroimidazole connected by a C-C bond (Kd = 700(80) nM). Our calculations reproduce the experimental affinities and uncover the recognition pattern between ligands' and their RNA target. They also provide a molecular basis for the markedly different affinity of the two ligands for CAG repeats as observed experimentally. These findings may pave the way for a structure-based hit-to-lead optimization to further improve ligand selectivity toward CAG repeat-containing mRNAs.
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Affiliation(s)
| | - Giulia Rossetti
- Department of Oncology, Hematology and Stem Cell Transplantation, RWTH Aachen University , D-52074 Aachen, North Rhine-Westphalia, Germany
| | - Oriana Tabarrini
- Department of Pharmaceutical Sciences, Università di Perugia , Via del Liceo 1, I-06123 Perugia, Perugia, Italy
| | - Sybille Krauβ
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Strasse 25, D-53127 Bonn, North Rhine-Westphalia, Germany
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27
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Frank AT, Zhang Q, Al-Hashimi HM, Andricioaei I. Slowdown of Interhelical Motions Induces a Glass Transition in RNA. Biophys J 2015; 108:2876-85. [PMID: 26083927 PMCID: PMC4472199 DOI: 10.1016/j.bpj.2015.04.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 03/21/2015] [Accepted: 04/21/2015] [Indexed: 12/29/2022] Open
Abstract
RNA function depends crucially on the details of its dynamics. The simplest RNA dynamical unit is a two-way interhelical junction. Here, for such a unit--the transactivation response RNA element--we present evidence from molecular dynamics simulations, supported by nuclear magnetic resonance relaxation experiments, for a dynamical transition near 230 K. This glass transition arises from the freezing out of collective interhelical motional modes. The motions, resolved with site-specificity, are dynamically heterogeneous and exhibit non-Arrhenius relaxation. The microscopic origin of the glass transition is a low-dimensional, slow manifold consisting largely of the Euler angles describing interhelical reorientation. Principal component analysis over a range of temperatures covering the glass transition shows that the abrupt slowdown of motion finds its explanation in a localization transition that traps probability density into several disconnected conformational pools over the low-dimensional energy landscape. Upon temperature increase, the probability density pools then flood a larger basin, akin to a lakes-to-sea transition. Simulations on transactivation response RNA are also used to backcalculate inelastic neutron scattering data that match previous inelastic neutron scattering measurements on larger and more complex RNA structures and which, upon normalization, give temperature-dependent fluctuation profiles that overlap onto a glass transition curve that is quasi-universal over a range of systems and techniques.
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Affiliation(s)
- Aaron T Frank
- Department of Chemistry, University of California at Irvine, Irvine, California
| | - Qi Zhang
- The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina
| | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina
| | - Ioan Andricioaei
- Department of Chemistry, University of California at Irvine, Irvine, California.
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28
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Mlýnský V, Kührová P, Zgarbová M, Jurečka P, Walter NG, Otyepka M, Šponer J, Banáš P. Reactive Conformation of the Active Site in the Hairpin Ribozyme Achieved by Molecular Dynamics Simulations with ε/ζ Force Field Reparametrizations. J Phys Chem B 2015; 119:4220-9. [DOI: 10.1021/jp512069n] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Vojtěch Mlýnský
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 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, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Marie Zgarbová
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Petr Jurečka
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Nils G. Walter
- Department
of Chemistry, Single Molecule Analysis Group, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Michal Otyepka
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
- CEITEC
− Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Banáš
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46 Olomouc, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
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29
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Panecka J, Šponer J, Trylska J. Conformational dynamics of bacterial and human cytoplasmic models of the ribosomal A-site. Biochimie 2015; 112:96-110. [PMID: 25748164 DOI: 10.1016/j.biochi.2015.02.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 02/23/2015] [Indexed: 01/12/2023]
Abstract
The aminoacyl-tRNA binding site (A-site) is located in helix 44 of small ribosomal subunit. The mobile adenines 1492 and 1493 (Escherichia coli numbering), forming the A-site bulge, act as a functional switch that ensures mRNA decoding accuracy. Structural data on the oligonucleotide models mimicking the ribosomal A-site with sequences corresponding to bacterial and human cytoplasmic sites confirm that this RNA motif forms also without the ribosome context. We performed all-atom molecular dynamics simulations of these crystallographic A-site models to compare their conformational properties. We found that the human A-site bulge is more internally flexible than the bacterial one and has different base pairing preferences, which result in the overall different shapes of these bulges and cation density distributions. Also, in the human A-site model we observed repetitive destacking of A1492, while A1493 was more stably paired than in the bacterial variant. Based on the dynamics of the A-sites we suggest why aminoglycoside antibiotics, which target the bacterial A-site, have lower binding affinities and anti-translational activities toward the human variant.
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Affiliation(s)
- Joanna Panecka
- Division of Biophysics, Institute of Experimental Physics, University of Warsaw, Żwirki i Wigury 93, 02-089 Warsaw, Poland; Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw, Pawińskiego 5a, 02-106 Warsaw, Poland
| | - Jiří Šponer
- CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic; Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic.
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland.
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30
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Abstract
Riboswitches are noncoding regulatory elements that control gene expression in response to the presence of metabolites, which bind to the aptamer domain. Metabolite binding appears to occur through a combination of conformational selection and induced fit mechanism. This demands to characterize the structural dynamics of the apo state of aptamer domains. In principle, molecular dynamics (MD) simulations can give insights at the atomistic level into the dynamics of the aptamer domain. However, it is unclear to what extent contemporary force fields can bias such insights. Here, we show that the Amber force field ff99 yields the best agreement with detailed experimental observations on differences in the structural dynamics of wild type and mutant aptamer domains of the guanine-sensing riboswitch (Gsw), including a pronounced influence of Mg2+. In contrast, applying ff99 with parmbsc0 and parmχOL modifications (denoted ff10) results in strongly damped motions and overly stable tertiary loop-loop interactions. These results are based on 58 MD simulations with an aggregate simulation time>11 μs, careful modeling of Mg2+ ions, and thorough statistical testing. Our results suggest that the moderate stabilization of the χ-anti region in ff10 can have an unwanted damping effect on functionally relevant structural dynamics of marginally stable RNA systems. This suggestion is supported by crystal structure analyses of Gsw aptamer domains that reveal χ torsions with high-anti values in the most mobile regions. We expect that future RNA force field development will benefit from considering marginally stable RNA systems and optimization toward good representations of dynamics in addition to structural characteristics.
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Affiliation(s)
- Christian A Hanke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
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31
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Mlýnský V, Walter NG, Šponer J, Otyepka M, Banáš P. The role of an active site Mg(2+) in HDV ribozyme self-cleavage: insights from QM/MM calculations. Phys Chem Chem Phys 2015; 17:670-9. [PMID: 25412464 PMCID: PMC4256098 DOI: 10.1039/c4cp03857f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The hepatitis delta virus (HDV) ribozyme is a catalytic RNA motif embedded in the human pathogenic HDV RNA. It catalyzes self-cleavage of its sugar-phosphate backbone with direct participation of the active site cytosine C75. Biochemical and structural data support a general acid role of C75. Here, we used hybrid quantum mechanical/molecular mechanical (QM/MM) calculations to probe the reaction mechanism and changes in Gibbs energy along the ribozyme's reaction pathway with an N3-protonated C75H(+) in the active site, which acts as the general acid, and a partially hydrated Mg(2+) ion with one deprotonated, inner-shell coordinated water molecule that acts as the general base. We followed eight reaction paths with a distinct position and coordination of the catalytically important active site Mg(2+) ion. For six of them, we observed feasible activation barriers ranging from 14.2 to 21.9 kcal mol(-1), indicating that the specific position of the Mg(2+) ion in the active site is predicted to strongly affect the kinetics of self-cleavage. The deprotonation of the U-1(2'-OH) nucleophile and the nucleophilic attack of the resulting U-1(2'-O(-)) on the scissile phosphodiester are found to be separate steps, as deprotonation precedes the nucleophilic attack. This sequential mechanism of the HDV ribozyme differs from the concerted nucleophilic activation and attack suggested for the hairpin ribozyme. We estimate the pKa of the U-1(2'-OH) group to range from 8.8 to 11.2, suggesting that it is lowered by several units from that of a free ribose, comparable to and most likely smaller than the pKa of the solvated active site Mg(2+) ion. Our results thus support the notion that the structure of the HDV ribozyme, and particularly the positioning of the active site Mg(2+) ion, facilitate deprotonation and activation of the 2'-OH nucleophile.
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Affiliation(s)
- Vojtěch Mlýnský
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, 771 46, Olomouc, Czech Republic.
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32
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Sripathi KN, Tay WW, Banáš P, Otyepka M, Šponer J, Walter NG. Disparate HDV ribozyme crystal structures represent intermediates on a rugged free-energy landscape. RNA (NEW YORK, N.Y.) 2014; 20:1112-28. [PMID: 24854621 PMCID: PMC4114689 DOI: 10.1261/rna.044982.114] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
The hepatitis delta virus (HDV) ribozyme is a member of the class of small, self-cleaving catalytic RNAs found in a wide range of genomes from HDV to human. Both pre- and post-catalysis (precursor and product) crystal structures of the cis-acting genomic HDV ribozyme have been determined. These structures, together with extensive solution probing, have suggested that a significant conformational change accompanies catalysis. A recent crystal structure of a trans-acting precursor, obtained at low pH and by molecular replacement from the previous product conformation, conforms to the product, raising the possibility that it represents an activated conformer past the conformational change. Here, using fluorescence resonance energy transfer (FRET), we discovered that cleavage of this ribozyme at physiological pH is accompanied by a structural lengthening in magnitude comparable to previous trans-acting HDV ribozymes. Conformational heterogeneity observed by FRET in solution appears to have been removed upon crystallization. Analysis of a total of 1.8 µsec of molecular dynamics (MD) simulations showed that the crystallographically unresolved cleavage site conformation is likely correctly modeled after the hammerhead ribozyme, but that crystal contacts and the removal of several 2'-oxygens near the scissile phosphate compromise catalytic in-line fitness. A cis-acting version of the ribozyme exhibits a more dynamic active site, while a G-1 residue upstream of the scissile phosphate favors poor fitness, allowing us to rationalize corresponding changes in catalytic activity. Based on these data, we propose that the available crystal structures of the HDV ribozyme represent intermediates on an overall rugged RNA folding free-energy landscape.
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Affiliation(s)
- Kamali N. Sripathi
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1065, USA
| | - Wendy W. Tay
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Pavel Banáš
- Regional Centre of Advance Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advance Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic
- Masaryk University, Campus Bohunice, 625 00 Brno, Czech Republic
| | - Nils G. Walter
- Department of Chemistry, Single Molecule Analysis Group, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
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33
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Šponer J, Banáš P, Jurečka P, Zgarbová M, Kührová P, Havrila M, Krepl M, Stadlbauer P, Otyepka M. Molecular Dynamics Simulations of Nucleic Acids. From Tetranucleotides to the Ribosome. J Phys Chem Lett 2014; 5:1771-82. [PMID: 26270382 DOI: 10.1021/jz500557y] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We present a brief overview of explicit solvent molecular dynamics (MD) simulations of nucleic acids. We explain physical chemistry limitations of the simulations, namely, the molecular mechanics (MM) force field (FF) approximation and limited time scale. Further, we discuss relations and differences between simulations and experiments, compare standard and enhanced sampling simulations, discuss the role of starting structures, comment on different versions of nucleic acid FFs, and relate MM computations with contemporary quantum chemistry. Despite its limitations, we show that MD is a powerful technique for studying the structural dynamics of nucleic acids with a fast growing potential that substantially complements experimental results and aids their interpretation.
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Affiliation(s)
- 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, Campus Bohunice, Kamenice 5, 625 00 Brno, 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
| | - Petr Jurečka
- §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
| | - Marie Zgarbová
- §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
| | - 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
| | - 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, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Miroslav Krepl
- †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
| | - 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
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Eichhorn CD, Kang M, Feigon J. Structure and function of preQ 1 riboswitches. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:939-950. [PMID: 24798077 DOI: 10.1016/j.bbagrm.2014.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 12/17/2022]
Abstract
PreQ1 riboswitches help regulate the biosynthesis and transport of preQ1 (7-aminomethyl-7-deazaguanine), a precursor of the hypermodified guanine nucleotide queuosine (Q), in a number of Firmicutes, Proteobacteria, and Fusobacteria. Queuosine is almost universally found at the wobble position of the anticodon in asparaginyl, tyrosyl, histidyl and aspartyl tRNAs, where it contributes to translational fidelity. Two classes of preQ1 riboswitches have been identified (preQ1-I and preQ1-II), and structures of examples from both classes have been determined. Both classes form H-type pseudoknots upon preQ1 binding, each of which has distinct unusual features and modes of preQ1 recognition. These features include an unusually long loop 2 in preQ1-I pseudoknots and an embedded hairpin in loop 3 in preQ1-II pseudoknots. PreQ1-I riboswitches are also notable for their unusually small aptamer domain, which has been extensively investigated by NMR, X-ray crystallography, FRET, and other biophysical methods. Here we review the discovery, structural biology, ligand specificity, cation interactions, folding, dynamics, and applications to biotechnology of preQ1 riboswitches. This article is part of a Special Issue entitled: Riboswitches.
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Affiliation(s)
- Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Mijeong Kang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA; UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA; UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA
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Disney MD, Yildirim I, Childs-Disney JL. Methods to enable the design of bioactive small molecules targeting RNA. Org Biomol Chem 2014; 12:1029-39. [PMID: 24357181 PMCID: PMC4020623 DOI: 10.1039/c3ob42023j] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
RNA is an immensely important target for small molecule therapeutics or chemical probes of function. However, methods that identify, annotate, and optimize RNA-small molecule interactions that could enable the design of compounds that modulate RNA function are in their infancies. This review describes recent approaches that have been developed to understand and optimize RNA motif-small molecule interactions, including structure-activity relationships through sequencing (StARTS), quantitative structure-activity relationships (QSAR), chemical similarity searching, structure-based design and docking, and molecular dynamics (MD) simulations. Case studies described include the design of small molecules targeting RNA expansions, the bacterial A-site, viral RNAs, and telomerase RNA. These approaches can be combined to afford a synergistic method to exploit the myriad of RNA targets in the transcriptome.
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Affiliation(s)
- Matthew D Disney
- The Department of Chemistry, The Scripps Research Institute, 130 Scripps Way #3A1, Jupiter, FL 33458, USA.
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Havrila M, Réblová K, Zirbel CL, Leontis NB, Šponer J. Isosteric and nonisosteric base pairs in RNA motifs: molecular dynamics and bioinformatics study of the sarcin-ricin internal loop. J Phys Chem B 2013; 117:14302-19. [PMID: 24144333 PMCID: PMC3946555 DOI: 10.1021/jp408530w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The sarcin-ricin RNA motif (SR motif) is one of the most prominent recurrent RNA building blocks that occurs in many different RNA contexts and folds autonomously, that is, in a context-independent manner. In this study, we combined bioinformatics analysis with explicit-solvent molecular dynamics (MD) simulations to better understand the relation between the RNA sequence and the evolutionary patterns of the SR motif. A SHAPE probing experiment was also performed to confirm the fidelity of the MD simulations. We identified 57 instances of the SR motif in a nonredundant subset of the RNA X-ray structure database and analyzed their base pairing, base-phosphate, and backbone-backbone interactions. We extracted sequences aligned to these instances from large rRNA alignments to determine the frequency of occurrence for different sequence variants. We then used a simple scoring scheme based on isostericity to suggest 10 sequence variants with a highly variable expected degree of compatibility with the SR motif 3D structure. We carried out MD simulations of SR motifs with these base substitutions. Nonisosteric base substitutions led to unstable structures, but so did isosteric substitutions which were unable to make key base-phosphate interactions. The MD technique explains why some potentially isosteric SR motifs are not realized during evolution. We also found that the inability to form stable cWW geometry is an important factor in the case of the first base pair of the flexible region of the SR motif. A comparison of structural, bioinformatics, SHAPE probing, and MD simulation data reveals that explicit solvent MD simulations neatly reflect the viability of different sequence variants of the SR motif. Thus, MD simulations can efficiently complement bioinformatics tools in studies of conservation patterns of RNA motifs and provide atomistic insight into the role of their different signature interactions.
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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
| | - Kamila Réblová
- CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Craig L. Zirbel
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Neocles B. Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - 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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Suddala KC, Rinaldi AJ, Feng J, Mustoe AM, Eichhorn CD, Liberman JA, Wedekind JE, Al-Hashimi HM, Brooks CL, Walter NG. Single transcriptional and translational preQ1 riboswitches adopt similar pre-folded ensembles that follow distinct folding pathways into the same ligand-bound structure. Nucleic Acids Res 2013; 41:10462-75. [PMID: 24003028 PMCID: PMC3905878 DOI: 10.1093/nar/gkt798] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Riboswitches are structural elements in the 5′ untranslated regions of many bacterial messenger RNAs that regulate gene expression in response to changing metabolite concentrations by inhibition of either transcription or translation initiation. The preQ1 (7-aminomethyl-7-deazaguanine) riboswitch family comprises some of the smallest metabolite sensing RNAs found in nature. Once ligand-bound, the transcriptional Bacillus subtilis and translational Thermoanaerobacter tengcongensis preQ1 riboswitch aptamers are structurally similar RNA pseudoknots; yet, prior structural studies have characterized their ligand-free conformations as largely unfolded and folded, respectively. In contrast, through single molecule observation, we now show that, at near-physiological Mg2+ concentration and pH, both ligand-free aptamers adopt similar pre-folded state ensembles that differ in their ligand-mediated folding. Structure-based Gō-model simulations of the two aptamers suggest that the ligand binds late (Bacillus subtilis) and early (Thermoanaerobacter tengcongensis) relative to pseudoknot folding, leading to the proposal that the principal distinction between the two riboswitches lies in their relative tendencies to fold via mechanisms of conformational selection and induced fit, respectively. These mechanistic insights are put to the test by rationally designing a single nucleotide swap distal from the ligand binding pocket that we find to predictably control the aptamers′ pre-folded states and their ligand binding affinities.
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Affiliation(s)
- Krishna C Suddala
- Biophysics, University of Michigan, Ann Arbor, MI 48109, USA, Single Molecule Analysis Group, University of Michigan, Ann Arbor, MI 48109, USA, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA, Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA, Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA and Center for Theoretical Biological Physics, University of California San Diego, San Diego, CA 92037, USA
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Huang W, Kim J, Jha S, Aboul-ela F. The impact of a ligand binding on strand migration in the SAM-I riboswitch. PLoS Comput Biol 2013; 9:e1003069. [PMID: 23704854 PMCID: PMC3656099 DOI: 10.1371/journal.pcbi.1003069] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 04/09/2013] [Indexed: 11/29/2022] Open
Abstract
Riboswitches sense cellular concentrations of small molecules and use this information to adjust synthesis rates of related metabolites. Riboswitches include an aptamer domain to detect the ligand and an expression platform to control gene expression. Previous structural studies of riboswitches largely focused on aptamers, truncating the expression domain to suppress conformational switching. To link ligand/aptamer binding to conformational switching, we constructed models of an S-adenosyl methionine (SAM)-I riboswitch RNA segment incorporating elements of the expression platform, allowing formation of an antiterminator (AT) helix. Using Anton, a computer specially developed for long timescale Molecular Dynamics (MD), we simulated an extended (three microseconds) MD trajectory with SAM bound to a modeled riboswitch RNA segment. Remarkably, we observed a strand migration, converting three base pairs from an antiterminator (AT) helix, characteristic of the transcription ON state, to a P1 helix, characteristic of the OFF state. This conformational switching towards the OFF state is observed only in the presence of SAM. Among seven extended trajectories with three starting structures, the presence of SAM enhances the trend towards the OFF state for two out of three starting structures tested. Our simulation provides a visual demonstration of how a small molecule (<500 MW) binding to a limited surface can trigger a large scale conformational rearrangement in a 40 kDa RNA by perturbing the Free Energy Landscape. Such a mechanism can explain minimal requirements for SAM binding and transcription termination for SAM-I riboswitches previously reported experimentally.
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Affiliation(s)
- Wei Huang
- Department of Biological Science, Louisiana State University, Baton Rouge, Louisiana, United States of America
- Center for Computation & Technology, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Joohyun Kim
- Center for Computation & Technology, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Shantenu Jha
- Center for Computation & Technology, Louisiana State University, Baton Rouge, Louisiana, United States of America
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, New Jersey, United States of America
| | - Fareed Aboul-ela
- Department of Biological Science, Louisiana State University, Baton Rouge, Louisiana, United States of America
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Krepl M, Réblová K, Koča J, Sponer J. Bioinformatics and molecular dynamics simulation study of L1 stalk non-canonical rRNA elements: kink-turns, loops, and tetraloops. J Phys Chem B 2013; 117:5540-55. [PMID: 23534440 DOI: 10.1021/jp401482m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The L1 stalk is a prominent mobile element of the large ribosomal subunit. We explore the structure and dynamics of its non-canonical rRNA elements, which include two kink-turns, an internal loop, and a tetraloop. We use bioinformatics to identify the L1 stalk RNA conservation patterns and carry out over 11.5 μs of MD simulations for a set of systems ranging from isolated RNA building blocks up to complexes of L1 stalk rRNA with the L1 protein and tRNA fragment. We show that the L1 stalk tetraloop has an unusual GNNA or UNNG conservation pattern deviating from major GNRA and YNMG RNA tetraloop families. We suggest that this deviation is related to a highly conserved tertiary contact within the L1 stalk. The available X-ray structures contain only UCCG tetraloops which in addition differ in orientation (anti vs syn) of the guanine. Our analysis suggests that the anti orientation might be a mis-refinement, although even the anti interaction would be compatible with the sequence pattern and observed tertiary interaction. Alternatively, the anti conformation may be a real substate whose population could be pH-dependent, since the guanine syn orientation requires protonation of cytosine in the tertiary contact. In absence of structural data, we use molecular modeling to explore the GCCA tetraloop that is dominant in bacteria and suggest that the GCCA tetraloop is structurally similar to the YNMG tetraloop. Kink-turn Kt-77 is unusual due to its 11-nucleotide bulge. The simulations indicate that the long bulge is a stalk-specific eight-nucleotide insertion into consensual kink-turn only subtly modifying its structural dynamics. We discuss a possible evolutionary role of helix H78 and a mechanism of L1 stalk interaction with tRNA. We also assess the simulation methodology. The simulations provide a good description of the studied systems with the latest bsc0χOL3 force field showing improved performance. Still, even bsc0χOL3 is unable to fully stabilize an essential sugar-edge H-bond between the bulge and non-canonical stem of the kink-turn. Inclusion of Mg(2+) ions may deteriorate the simulations. On the other hand, monovalent ions can in simulations readily occupy experimental Mg(2+) binding sites.
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Affiliation(s)
- Miroslav Krepl
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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40
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Henriksen NM, Roe DR, Cheatham TE. Reliable oligonucleotide conformational ensemble generation in explicit solvent for force field assessment using reservoir replica exchange molecular dynamics simulations. J Phys Chem B 2013; 117:4014-27. [PMID: 23477537 PMCID: PMC3775460 DOI: 10.1021/jp400530e] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular dynamics force field development and assessment requires a reliable means for obtaining a well-converged conformational ensemble of a molecule in both a time-efficient and cost-effective manner. This remains a challenge for RNA because its rugged energy landscape results in slow conformational sampling and accurate results typically require explicit solvent which increases computational cost. To address this, we performed both traditional and modified replica exchange molecular dynamics simulations on a test system (alanine dipeptide) and an RNA tetramer known to populate A-form-like conformations in solution (single-stranded rGACC). A key focus is on providing the means to demonstrate that convergence is obtained, for example, by investigating replica RMSD profiles and/or detailed ensemble analysis through clustering. We found that traditional replica exchange simulations still require prohibitive time and resource expenditures, even when using GPU accelerated hardware, and our results are not well converged even at 2 μs of simulation time per replica. In contrast, a modified version of replica exchange, reservoir replica exchange in explicit solvent, showed much better convergence and proved to be both a cost-effective and reliable alternative to the traditional approach. We expect this method will be attractive for future research that requires quantitative conformational analysis from explicitly solvated simulations.
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Affiliation(s)
- Niel M. Henriksen
- Department of Medicinal Chemistry, College of Pharmacy, 2000 East 30 South Skaggs 201, University of Utah, Salt Lake City, UT, 84112, USA
| | - Daniel R. Roe
- Department of Medicinal Chemistry, College of Pharmacy, 2000 East 30 South Skaggs 201, University of Utah, Salt Lake City, UT, 84112, USA
| | - Thomas E. Cheatham
- Department of Medicinal Chemistry, College of Pharmacy, 2000 East 30 South Skaggs 201, University of Utah, Salt Lake City, UT, 84112, USA
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41
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Kührová P, Banáš P, Best RB, Šponer J, Otyepka M. Computer Folding of RNA Tetraloops? Are We There Yet? J Chem Theory Comput 2013; 9:2115-25. [DOI: 10.1021/ct301086z] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- 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
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
| | - Robert B. Best
- Laboratory of Chemical Physics,
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520,
United States
| | - Jiří Šponer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
- 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, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
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Islam B, Sgobba M, Laughton C, Orozco M, Sponer J, Neidle S, Haider S. Conformational dynamics of the human propeller telomeric DNA quadruplex on a microsecond time scale. Nucleic Acids Res 2013; 41:2723-35. [PMID: 23293000 PMCID: PMC3575793 DOI: 10.1093/nar/gks1331] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 11/26/2012] [Accepted: 11/27/2012] [Indexed: 01/12/2023] Open
Abstract
The human telomeric DNA sequence with four repeats can fold into a parallel-stranded propeller-type topology. NMR structures solved under molecular crowding experiments correlate with the crystal structures found with crystal-packing interactions that are effectively equivalent to molecular crowding. This topology has been used for rationalization of ligand design and occurs experimentally in a number of complexes with a diversity of ligands, at least in the crystalline state. Although G-quartet stems have been well characterized, the interactions of the TTA loop with the G-quartets are much less defined. To better understand the conformational variability and structural dynamics of the propeller-type topology, we performed molecular dynamics simulations in explicit solvent up to 1.5 μs. The analysis provides a detailed atomistic account of the dynamic nature of the TTA loops highlighting their interactions with the G-quartets including formation of an A:A base pair, triad, pentad and hexad. The results present a threshold in quadruplex simulations, with regards to understanding the flexible nature of the sugar-phosphate backbone in formation of unusual architecture within the topology. Furthermore, this study stresses the importance of simulation time in sampling conformational space for this topology.
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Affiliation(s)
- Barira Islam
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Miriam Sgobba
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Charlie Laughton
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Modesto Orozco
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Jiri Sponer
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Stephen Neidle
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
| | - Shozeb Haider
- Centre for Cancer Research and Cell Biology, Queen’s University of Belfast, Belfast BT9 7BL, UK, School of Pharmacy, Nottingham University, University Park, Nottingham NG7 2RD, UK, Institute of Research in Biomedicine, Barcelona 08028, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovoplka 135, Brno 612 65, Czech Republic, Central European Institute of Technology, Campus Bohunice, Kamenice 5, Brno 625 00, Czech Republic and University College London, School of Pharmacy, Brunswick Square, London WC1N 1AX, UK
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