1
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Linzer JT, Aminov E, Abdullah AS, Kirkup CE, Diaz Ventura RI, Bijoor VR, Jung J, Huang S, Tse CG, Álvarez Toucet E, Onghai HP, Ghosh AP, Grodzki AC, Haines ER, Iyer AS, Khalil MK, Leong AP, Neuhaus MA, Park J, Shahid A, Xie M, Ziembicki JM, Simmerling C, Nagan MC. Accurately Modeling RNA Stem-Loops in an Implicit Solvent Environment. J Chem Inf Model 2024. [PMID: 39002142 DOI: 10.1021/acs.jcim.4c00756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2024]
Abstract
Ribonucleic acid (RNA) molecules can adopt a variety of secondary and tertiary structures in solution, with stem-loops being one of the more common motifs. Here, we present a systematic analysis of 15 RNA stem-loop sequences simulated with molecular dynamics simulations in an implicit solvent environment. Analysis of RNA cluster ensembles showed that the stem-loop structures can generally adopt the A-form RNA in the stem region. Loop structures are more sensitive, and experimental structures could only be reproduced with modification of CH···O interactions in the force field, combined with an implicit solvent nonpolar correction to better model base stacking interactions. Accurately modeling RNA with current atomistic physics-based models remains challenging, but the RNA systems studied herein may provide a useful benchmark set for testing other RNA modeling methods in the future.
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Affiliation(s)
- Jason T Linzer
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Ethan Aminov
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Aalim S Abdullah
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Colleen E Kirkup
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Rebeca I Diaz Ventura
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Vinay R Bijoor
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Jiyun Jung
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Sophie Huang
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Chi Gee Tse
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Emily Álvarez Toucet
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Hugo P Onghai
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Arghya P Ghosh
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Alex C Grodzki
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Emilee R Haines
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Aditya S Iyer
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Mark K Khalil
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Alexander P Leong
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Michael A Neuhaus
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Joseph Park
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Asir Shahid
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Matthew Xie
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Jan M Ziembicki
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Carlos Simmerling
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Maria C Nagan
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
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2
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Traoré D, Biecher E, Mallet M, Rouanet S, Vasseur JJ, Smietana M, Dupouy C. Synthesis and properties of RNA constrained by a 2'-O-disulfide bridge. ChemistryOpen 2024:e202300232. [PMID: 38200655 DOI: 10.1002/open.202300232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Indexed: 01/12/2024] Open
Abstract
We recently reported the properties of RNA hairpins constrained by a dimethylene (DME) disulfide (S-S) linker incorporated between two adjacent nucleosides in the loop and showed that this linker locked the hairpin conformation thus disturbing the duplex/hairpin equilibrium. We have now investigated the influence of the length of the linker and synthesized oligoribonucleotides containing diethylene (DEE) and dipropylene (DPE) S-S bridges. This was achieved via the preparation of building blocks, namely 2'-O-acetylthioethyl (2'-O-AcSE) and 2'-O-acetylthiopropyl (2'-O-AcSP) uridine phosphoramidites, which were successfully incorporated into RNA sequences. Thermal denaturation analysis revealed that the DEE and DPE disulfide bridges destabilize RNA duplexes but do not disrupt the hairpin conformation. Furthermore, our investigation of the duplex/hairpin equilibrium indicated that sequences modified with DME and DEE S-S linkers predominantly lock the hairpin form, whereas the DPE S-S linker provides flexibility. These findings highlight the potential of S-S linkers to study RNA interactions.
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Affiliation(s)
- Diallo Traoré
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Elisa Biecher
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Manon Mallet
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Sonia Rouanet
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | | | - Michael Smietana
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Christelle Dupouy
- CNRS, ENSCM, 1919 route de Mende, 34293, Montpellier Cedex 5, France
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3
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Grille L, Gallego D, Darré L, da Rosa G, Battistini F, Orozco M, Dans PD. The pseudotorsional space of RNA. RNA (NEW YORK, N.Y.) 2023; 29:1896-1909. [PMID: 37793790 PMCID: PMC10653382 DOI: 10.1261/rna.079821.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023]
Abstract
The characterization of the conformational landscape of the RNA backbone is rather complex due to the ability of RNA to assume a large variety of conformations. These backbone conformations can be depicted by pseudotorsional angles linking RNA backbone atoms, from which Ramachandran-like plots can be built. We explore here different definitions of these pseudotorsional angles, finding that the most accurate ones are the traditional η (eta) and θ (theta) angles, which represent the relative position of RNA backbone atoms P and C4'. We explore the distribution of η - θ in known experimental structures, comparing the pseudotorsional space generated with structures determined exclusively by one experimental technique. We found that the complete picture only appears when combining data from different sources. The maps provide a quite comprehensive representation of the RNA accessible space, which can be used in RNA-structural predictions. Finally, our results highlight that protein interactions lead to significant changes in the population of the η - θ space, pointing toward the role of induced-fit mechanisms in protein-RNA recognition.
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Affiliation(s)
- Leandro Grille
- Computational Biophysics Group, Department of Biological Sciences, CENUR Litoral Norte, Universidad de la República, 50000 Salto, Uruguay
- Bioinformatics Unit, Institute Pasteur of Montevideo, 11400 Montevideo, Uruguay
| | - Diego Gallego
- Molecular Modelling and Bioinformatics Group, Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Leonardo Darré
- Bioinformatics Unit, Institute Pasteur of Montevideo, 11400 Montevideo, Uruguay
- Molecular Modelling and Bioinformatics Group, Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Gabriela da Rosa
- Computational Biophysics Group, Department of Biological Sciences, CENUR Litoral Norte, Universidad de la República, 50000 Salto, Uruguay
- Bioinformatics Unit, Institute Pasteur of Montevideo, 11400 Montevideo, Uruguay
| | - Federica Battistini
- Molecular Modelling and Bioinformatics Group, Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Modesto Orozco
- Molecular Modelling and Bioinformatics Group, Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Pablo D Dans
- Computational Biophysics Group, Department of Biological Sciences, CENUR Litoral Norte, Universidad de la República, 50000 Salto, Uruguay
- Bioinformatics Unit, Institute Pasteur of Montevideo, 11400 Montevideo, Uruguay
- Molecular Modelling and Bioinformatics Group, Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
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4
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Tieng FYF, Abdullah-Zawawi MR, Md Shahri NAA, Mohamed-Hussein ZA, Lee LH, Mutalib NSA. A Hitchhiker's guide to RNA-RNA structure and interaction prediction tools. Brief Bioinform 2023; 25:bbad421. [PMID: 38040490 PMCID: PMC10753535 DOI: 10.1093/bib/bbad421] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/16/2023] [Accepted: 10/26/2023] [Indexed: 12/03/2023] Open
Abstract
RNA biology has risen to prominence after a remarkable discovery of diverse functions of noncoding RNA (ncRNA). Most untranslated transcripts often exert their regulatory functions into RNA-RNA complexes via base pairing with complementary sequences in other RNAs. An interplay between RNAs is essential, as it possesses various functional roles in human cells, including genetic translation, RNA splicing, editing, ribosomal RNA maturation, RNA degradation and the regulation of metabolic pathways/riboswitches. Moreover, the pervasive transcription of the human genome allows for the discovery of novel genomic functions via RNA interactome investigation. The advancement of experimental procedures has resulted in an explosion of documented data, necessitating the development of efficient and precise computational tools and algorithms. This review provides an extensive update on RNA-RNA interaction (RRI) analysis via thermodynamic- and comparative-based RNA secondary structure prediction (RSP) and RNA-RNA interaction prediction (RIP) tools and their general functions. We also highlighted the current knowledge of RRIs and the limitations of RNA interactome mapping via experimental data. Then, the gap between RSP and RIP, the importance of RNA homologues, the relationship between pseudoknots, and RNA folding thermodynamics are discussed. It is hoped that these emerging prediction tools will deepen the understanding of RNA-associated interactions in human diseases and hasten treatment processes.
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Affiliation(s)
- Francis Yew Fu Tieng
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
| | | | - Nur Alyaa Afifah Md Shahri
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
| | - Zeti-Azura Mohamed-Hussein
- Institute of Systems Biology (INBIOSIS), UKM, Selangor 43600, Malaysia
- Department of Applied Physics, Faculty of Science and Technology, UKM, Selangor 43600, Malaysia
| | - Learn-Han Lee
- Sunway Microbiomics Centre, School of Medical and Life Sciences, Sunway University, Sunway City 47500, Malaysia
- Novel Bacteria and Drug Discovery Research Group, Microbiome and Bioresource Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University of Malaysia, Selangor 47500, Malaysia
| | - Nurul-Syakima Ab Mutalib
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
- Novel Bacteria and Drug Discovery Research Group, Microbiome and Bioresource Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University of Malaysia, Selangor 47500, Malaysia
- Faculty of Health Sciences, UKM, Kuala Lumpur 50300, Malaysia
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5
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Schneider B, Sweeney BA, Bateman A, Cerny J, Zok T, Szachniuk M. When will RNA get its AlphaFold moment? Nucleic Acids Res 2023; 51:9522-9532. [PMID: 37702120 PMCID: PMC10570031 DOI: 10.1093/nar/gkad726] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/13/2023] [Accepted: 08/22/2023] [Indexed: 09/14/2023] Open
Abstract
The protein structure prediction problem has been solved for many types of proteins by AlphaFold. Recently, there has been considerable excitement to build off the success of AlphaFold and predict the 3D structures of RNAs. RNA prediction methods use a variety of techniques, from physics-based to machine learning approaches. We believe that there are challenges preventing the successful development of deep learning-based methods like AlphaFold for RNA in the short term. Broadly speaking, the challenges are the limited number of structures and alignments making data-hungry deep learning methods unlikely to succeed. Additionally, there are several issues with the existing structure and sequence data, as they are often of insufficient quality, highly biased and missing key information. Here, we discuss these challenges in detail and suggest some steps to remedy the situation. We believe that it is possible to create an accurate RNA structure prediction method, but it will require solving several data quality and volume issues, usage of data beyond simple sequence alignments, or the development of new less data-hungry machine learning methods.
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Affiliation(s)
- Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, CZ-252 50 Vestec, Czech Republic
| | - Blake Alexander Sweeney
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, CB10 1SD, UK
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, CB10 1SD, UK
| | - Jiri Cerny
- Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, CZ-252 50 Vestec, Czech Republic
| | - Tomasz Zok
- Institute of Computing Science and European Centre for Bioinformatics and Genomics, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
| | - Marta Szachniuk
- Institute of Computing Science and European Centre for Bioinformatics and Genomics, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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6
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Shraim AS, Abdel Majeed BA, Al-Binni M, Hunaiti A. Therapeutic Potential of Aptamer-Protein Interactions. ACS Pharmacol Transl Sci 2022; 5:1211-1227. [PMID: 36524009 PMCID: PMC9745894 DOI: 10.1021/acsptsci.2c00156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Indexed: 11/06/2022]
Abstract
Aptamers are single-stranded oligonucleotides (RNA or DNA) with a typical length between 25 and 100 nucleotides which fold into three-dimensional structures capable of binding to target molecules. Specific aptamers can be isolated against a large variety of targets through efficient and relatively cheap methods, and they demonstrate target-binding affinities that sometimes surpass those of antibodies. Consequently, interest in aptamers has surged over the past three decades, and their application has shown promise in advancing knowledge in target analysis, designing therapeutic interventions, and bioengineering. With emphasis on their therapeutic applications, aptamers are emerging as a new innovative class of therapeutic agents with promising biochemical and biological properties. Aptamers have the potential of providing a feasible alternative to antibody- and small-molecule-based therapeutics given their binding specificity, stability, low toxicity, and apparent non-immunogenicity. This Review examines the general properties of aptamers and aptamer-protein interactions that help to understand their binding characteristics and make them important therapeutic candidates.
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Affiliation(s)
- Ala’a S. Shraim
- Department
of Medical Laboratory Sciences, Faculty of Allied Medical Sciences, Al-Ahliyya Amman University, 19328 Amman, Jordan
- Pharmacological
and Diagnostic Research Center (PDRC), Al-Ahliyya
Amman University, 19328 Amman, Jordan
| | - Bayan A. Abdel Majeed
- Department
of Medical Laboratory Sciences, Faculty of Allied Medical Sciences, Al-Ahliyya Amman University, 19328 Amman, Jordan
- Pharmacological
and Diagnostic Research Center (PDRC), Al-Ahliyya
Amman University, 19328 Amman, Jordan
| | - Maysaa’
Adnan Al-Binni
- Department
of Clinical Laboratory Sciences, School of Science, The University of Jordan, 11942 Amman, Jordan
| | - Abdelrahim Hunaiti
- Department
of Clinical Laboratory Sciences, School of Science, The University of Jordan, 11942 Amman, Jordan
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7
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Zhang D, Li Y, Zhong Q, Wang A, Weng J, Gong L, Li G. Ribonucleic Acid Folding Prediction Based on Iterative Multiscale Simulation. J Phys Chem Lett 2022; 13:9957-9966. [PMID: 36260782 DOI: 10.1021/acs.jpclett.2c01342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
RNA folding prediction is a challenge. Currently, many RNA folding models are coarse-grained (CG) with the potential derived from the known RNA structures. However, this potential is not suitable for modified and entirely new RNA. It is also not suitable for the folding simulation of RNA in the real cellular environment, including many kinds of molecular interactions. In contrast, our proposed model has the potential to address these issues, which is a multiscale simulation scheme based on all-atom (AA) force fields. We fit the CG force field using the trajectories generated by the AA force field and then iteratively perform molecular dynamics (MD) simulations of the two scales. The all-atom molecular dynamics (AAMD) simulation is mainly responsible for the correction of RNA structure, and the CGMD simulation is mainly responsible for efficient conformational sampling. On the basis of this scheme, we can successfully fold three RNAs belonging to a hairpin, a pseudoknot, and a four-way junction.
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Affiliation(s)
- Dinglin Zhang
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
- Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100049, P. R. China
| | - Yan Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
| | - Qinglu Zhong
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
| | - Anhui Wang
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
| | - Junben Weng
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
- Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100049, P. R. China
| | - Lidong Gong
- School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian116029, China
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, P. R. China
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8
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González-Alemán R, Chevrollier N, Simoes M, Montero-Cabrera L, Leclerc F. MCSS-Based Predictions of Binding Mode and Selectivity of Nucleotide Ligands. J Chem Theory Comput 2021; 17:2599-2618. [PMID: 33764770 DOI: 10.1021/acs.jctc.0c01339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Computational fragment-based approaches are widely used in drug design and discovery. One of their limitations is the lack of performance of docking methods, mainly the scoring functions. With the emergence of fragment-based approaches for single-stranded RNA ligands, we analyze the performance in docking and screening powers of an MCSS-based approach. The performance is evaluated on a benchmark of protein-nucleotide complexes where the four RNA residues are used as fragments. The screening power can be considered the major limiting factor for the fragment-based modeling or design of sequence-selective oligonucleotides. We show that the MCSS sampling is efficient even for such large and flexible fragments. Hybrid solvent models based on some partial explicit representations improve both the docking and screening powers. Clustering of the n best-ranked poses can also contribute to a lesser extent to better performance. A detailed analysis of molecular features suggests various ways to optimize the performance further.
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Affiliation(s)
- Roy González-Alemán
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Saclay, Gif-sur-Yvette F-91198, France.,Laboratorio de Química Computacional y Teórica (LQCT), Facultad de Química, Universidad de La Habana, 10400 La Habana, Cuba
| | - Nicolas Chevrollier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Saclay, Gif-sur-Yvette F-91198, France
| | - Manuel Simoes
- CPC Manufacturing Analytics, 67000 Strasbourg, France
| | - Luis Montero-Cabrera
- Laboratorio de Química Computacional y Teórica (LQCT), Facultad de Química, Universidad de La Habana, 10400 La Habana, Cuba
| | - Fabrice Leclerc
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Saclay, Gif-sur-Yvette F-91198, France
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9
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Černý J, Božíková P, Malý M, Tykač M, Biedermannová L, Schneider B. Structural alphabets for conformational analysis of nucleic acids available at dnatco.datmos.org. Acta Crystallogr D Struct Biol 2020; 76:805-813. [PMID: 32876056 PMCID: PMC7466747 DOI: 10.1107/s2059798320009389] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023] Open
Abstract
A detailed description of the dnatco.datmos.org web server implementing the universal structural alphabet of nucleic acids is presented. It is capable of processing any mmCIF- or PDB-formatted files containing DNA or RNA molecules; these can either be uploaded by the user or supplied as the wwPDB or PDB-REDO structural database access code. The web server performs an assignment of the nucleic acid conformations and presents the results for the intuitive annotation, validation, modeling and refinement of nucleic acids.
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Affiliation(s)
- Jiří Černý
- Laboratory of Structural Bioinformatics of Proteins, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
| | - Paulína Božíková
- Laboratory of Structural Bioinformatics of Proteins, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
| | - Michal Malý
- Laboratory of Structural Bioinformatics of Proteins, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
| | - Michal Tykač
- Laboratory of Structural Bioinformatics of Proteins, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
| | - Lada Biedermannová
- Laboratory of Biomolecular Recognition, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
| | - Bohdan Schneider
- Laboratory of Biomolecular Recognition, Institute of Biotechnology of the Czech Academy of Sciences, Prumyslova 595, Vestec, Czech Republic
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10
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Černý J, Božíková P, Svoboda J, Schneider B. A unified dinucleotide alphabet describing both RNA and DNA structures. Nucleic Acids Res 2020; 48:6367-6381. [PMID: 32406923 PMCID: PMC7293047 DOI: 10.1093/nar/gkaa383] [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: 04/11/2020] [Revised: 04/11/2020] [Accepted: 04/30/2020] [Indexed: 12/13/2022] Open
Abstract
By analyzing almost 120 000 dinucleotides in over 2000 nonredundant nucleic acid crystal structures, we define 96+1 diNucleotide Conformers, NtCs, which describe the geometry of RNA and DNA dinucleotides. NtC classes are grouped into 15 codes of the structural alphabet CANA (Conformational Alphabet of Nucleic Acids) to simplify symbolic annotation of the prominent structural features of NAs and their intuitive graphical display. The search for nontrivial patterns of NtCs resulted in the identification of several types of RNA loops, some of them observed for the first time. Over 30% of the nearly six million dinucleotides in the PDB cannot be assigned to any NtC class but we demonstrate that up to a half of them can be re-refined with the help of proper refinement targets. A statistical analysis of the preferences of NtCs and CANA codes for the 16 dinucleotide sequences showed that neither the NtC class AA00, which forms the scaffold of RNA structures, nor BB00, the DNA most populated class, are sequence neutral but their distributions are significantly biased. The reported automated assignment of the NtC classes and CANA codes available at dnatco.org provides a powerful tool for unbiased analysis of nucleic acid structures by structural and molecular biologists.
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Affiliation(s)
- Jiří Černý
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, CZ-252 50 Vestec, Prague-West, Czech Republic
| | - Paulína Božíková
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, CZ-252 50 Vestec, Prague-West, Czech Republic
| | - Jakub Svoboda
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, CZ-252 50 Vestec, Prague-West, Czech Republic
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, CZ-252 50 Vestec, Prague-West, Czech Republic
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11
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A deep learning framework to predict binding preference of RNA constituents on protein surface. Nat Commun 2019; 10:4941. [PMID: 31666519 PMCID: PMC6821705 DOI: 10.1038/s41467-019-12920-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/08/2019] [Indexed: 12/21/2022] Open
Abstract
Protein-RNA interaction plays important roles in post-transcriptional regulation. However, the task of predicting these interactions given a protein structure is difficult. Here we show that, by leveraging a deep learning model NucleicNet, attributes such as binding preference of RNA backbone constituents and different bases can be predicted from local physicochemical characteristics of protein structure surface. On a diverse set of challenging RNA-binding proteins, including Fem-3-binding-factor 2, Argonaute 2 and Ribonuclease III, NucleicNet can accurately recover interaction modes discovered by structural biology experiments. Furthermore, we show that, without seeing any in vitro or in vivo assay data, NucleicNet can still achieve consistency with experiments, including RNAcompete, Immunoprecipitation Assay, and siRNA Knockdown Benchmark. NucleicNet can thus serve to provide quantitative fitness of RNA sequences for given binding pockets or to predict potential binding pockets and binding RNAs for previously unknown RNA binding proteins.
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12
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Unveiling the druggable RNA targets and small molecule therapeutics. Bioorg Med Chem 2019; 27:2149-2165. [PMID: 30981606 PMCID: PMC7126819 DOI: 10.1016/j.bmc.2019.03.057] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/25/2019] [Accepted: 03/29/2019] [Indexed: 12/15/2022]
Abstract
The increasing appreciation for the crucial roles of RNAs in infectious and non-infectious human diseases makes them attractive therapeutic targets. Coding and non-coding RNAs frequently fold into complex conformations which, if effectively targeted, offer opportunities to therapeutically modulate numerous cellular processes, including those linked to undruggable protein targets. Despite the considerable skepticism as to whether RNAs can be targeted with small molecule therapeutics, overwhelming evidence suggests the challenges we are currently facing are not outside the realm of possibility. In this review, we highlight the most recent advances in molecular techniques that have sparked a revolution in understanding the RNA structure-to-function relationship. We bring attention to the application of these modern techniques to identify druggable RNA targets and to assess small molecule binding specificity. Finally, we discuss novel screening methodologies that support RNA drug discovery and present examples of therapeutically valuable RNA targets.
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13
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Malicki S, Ksiazek M, Majewski P, Pecak A, Mydel P, Grudnik P, Dubin G. Development of a novel, high-affinity ssDNA trypsin inhibitor. J Enzyme Inhib Med Chem 2019; 34:638-643. [PMID: 30727784 PMCID: PMC6366424 DOI: 10.1080/14756366.2019.1569648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Inhibitors of serine proteases are not only extremely useful in the basic research but are also applied extensively in clinical settings. Using Systematic Evolution of Ligands by Exponential Enrichment (SELEX) approach we developed a family of novel, single-stranded DNA aptamers capable of specific trypsin inhibition. Our most potent candidate (T24) and its short version (T59) were thoroughly characterised in terms of efficacy. T24 and T59 efficiently inhibited bovine trypsin with Ki of 176 nM and 475 nM, respectively. Interestingly, in contrast to the majority of known trypsin inhibitors, the selected aptamers have superior specificity and did not interact with porcine trypsin or any human proteases tested. These included plasmin and thrombin characterised by trypsin-like substrate specificity. Our results demonstrate that SELEX may be successfully employed in the development of potent and specific DNA based protease inhibitors.
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Affiliation(s)
- Stanislaw Malicki
- a Malopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland.,b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland
| | - Miroslaw Ksiazek
- a Malopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland.,b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland.,c Department of Oral Immunology and Infectious Diseases , University of Louisville School of Dentistry , Kentucky , USA
| | - Pawel Majewski
- b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland
| | - Aleksandra Pecak
- a Malopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland.,b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland
| | - Piotr Mydel
- b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland.,d Department of Clinical Science , Broegelmann Research Laboratory, University of Bergen , Bergen , Norway
| | - Przemyslaw Grudnik
- a Malopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland
| | - Grzegorz Dubin
- a Malopolska Centre of Biotechnology , Jagiellonian University , Krakow , Poland.,b Department of Microbiology, Faculty of Biochemistry , Biophysics and Biotechnology, Jagiellonian University , Krakow , Poland
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14
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Wales DJ, Disney MD, Yildirim I. Computational Investigation of RNA A-Bulges Related to the Microtubule-Associated Protein Tau Causing Frontotemporal Dementia and Parkinsonism. J Phys Chem B 2019; 123:57-65. [PMID: 30517788 PMCID: PMC6465094 DOI: 10.1021/acs.jpcb.8b09139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mutations in the human tau gene result in alternative splicing of the tau protein, which causes frontotemporal dementia and Parkinsonism. One disease mechanism is linked to the stability of a hairpin within the microtubule-associated protein tau (MAPT) mRNA, which contains an A-bulge. Here we employ computational methods to investigate the structural and thermodynamic properties of several A-bulge RNAs with different closing base-pairs. We find that the current amber RNA force field has a preference to overstabilize base-triple over stacked states, even though some of the A-bulges are known to prefer stacked states according to NMR studies. We further determined that if the neighboring base-pairs of A-bulges are AU, this situation can lead to base slippage. However, when the 3'-side of the A-bulge has an UA base-pair, the stacked state is stabilized by an extra interaction that is not observed in the other sequences. We suggest that these A-bulge RNA systems could be used as benchmarks to improve the current RNA force fields.
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Affiliation(s)
- David J. Wales
- Department of Chemistry, University of Cambridge, Cambridge, Cambridgeshire CB2 1EW, U.K
| | - Matthew D. Disney
- Department of Chemistry, Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Ilyas Yildirim
- Department of Chemistry, Scripps Research Institute, Jupiter, Florida 33458, United States
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
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15
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16
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Eltzner B, Huckemann S, Mardia KV. Torus principal component analysis with applications to RNA structure. Ann Appl Stat 2018. [DOI: 10.1214/17-aoas1115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Meier M, Moya-Torres A, Krahn NJ, McDougall MD, Orriss GL, McRae EK, Booy EP, McEleney K, Patel TR, McKenna SA, Stetefeld J. Structure and hydrodynamics of a DNA G-quadruplex with a cytosine bulge. Nucleic Acids Res 2018; 46:5319-5331. [PMID: 29718405 PMCID: PMC6007744 DOI: 10.1093/nar/gky307] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 04/05/2018] [Accepted: 04/12/2018] [Indexed: 12/27/2022] Open
Abstract
The identification of four-stranded G-quadruplexes (G4s) has highlighted the fact that DNA has additional spatial organisations at its disposal other than double-stranded helices. Recently, it became clear that the formation of G4s is not limited to the traditional G3+NL1G3+NL2G3+NL3G3+ sequence motif. Instead, the G3 triplets can be interrupted by deoxythymidylate (DNA) or uridylate (RNA) where the base forms a bulge that loops out from the G-quadruplex core. Here, we report the first high-resolution X-ray structure of a unique unimolecular DNA G4 with a cytosine bulge. The G4 forms a dimer that is stacked via its 5'-tetrads. Analytical ultracentrifugation, static light scattering and small angle X-ray scattering confirmed that the G4 adapts a predominantly dimeric structure in solution. We provide a comprehensive comparison of previously published G4 structures containing bulges and report a special γ torsion angle range preferentially populated by the G4 core guanylates adjacent to bulges. Since the penalty for introducing bulges appears to be negligible, it should be possible to functionalize G4s by introducing artificial or modified nucleotides at such positions. The presence of the bulge alters the surface of the DNA, providing an opportunity to develop drugs that can specifically target individual G4s.
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Affiliation(s)
- Markus Meier
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Aniel Moya-Torres
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Natalie J Krahn
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Matthew D McDougall
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - George L Orriss
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Ewan K S McRae
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Evan P Booy
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Kevin McEleney
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Trushar R Patel
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
- DiscoveryLab, Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary T2N 1N4, Alberta, Canada
| | - Sean A McKenna
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Jörg Stetefeld
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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18
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Minguirbara A, Nsangou M. DFT study of geometrical and vibrational features of a 3',5'-deoxydisugar-monophosphate (dDSMP) DNA model in the presence of counterions and solvent. J Mol Model 2018. [PMID: 29516189 DOI: 10.1007/s00894-018-3629-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The B3LYP/6-31++G* theoretical level was used to study the influence of various hexahydrated monovalent (Li+, Na+, K+) and divalent (Mg2+) metal counterions in interaction with the charged PO2- group, on the geometrical and vibrational characteristics of the DNA fragments of 3',5'-dDSMP, represented by four conformers (g+g+, g+t, g-g- and g-t). All complexes were optimized through two solvation models [the explicit model (6H2O) and the hybrid model (6H2O/Continuum)]. The results obtained established that, in the hybrid model, counterions (Li+, Na+, K+, Mg2+) always remain in the bisector plane of the O1-P-O2 angle. When these counterions are explicitly hydrated, the smallest counterions (Li+, Na+) deviate from the bisector plane, while the largest counterions (K+ and Mg2+) always remain in the same plane. On the other hand, the present calculations reveal that the g+g+ conformer is the most stable in the presence of monovalent counterions, while conformers g+t and g-t are the most stable in the presence of the divalent counterion Mg2+. Finally, the hybrid solvation model seems to be in better agreement with the available crystallographic and spectroscopic (Raman) experiments than the explicit model. Indeed, the six conformational torsions of the C4'-C3'-O3'-PO-2-O5'-C5'-C4' segment of all complexes of the g-g- conformer in 6H2O/Continuum remain similar to the available experimental data of A- and B-DNA forms. The calculated wavenumbers of the g+g+ conformer in the presence of the monovalent counterion and of g-t conformer in presence of the divalent counterion in the hybrid model are in good agreement with the Raman experimental data of A- and B-DNA forms. In addition, the maximum deviation between the calculated wavenumbers in the 6H2O/Continuum for the g+g+ conformer and experimental value measured in an aqueous solution of the DMP-Na+ complex, is <1.07% for the PO2- (asymmetric and symmetric) stretching modes and <2.03% for the O5'-C5' and O3'-C3' stretching modes. Graphical abstract dDSMP-(OO)- Mg2+/6W/Continuum.
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Affiliation(s)
- Alain Minguirbara
- Department of Physics, Higher Teachers' Training College, University of Maroua, PO Box 46, Maroua, Cameroon
| | - Mama Nsangou
- Department of Physics, Higher Teachers' Training College, University of Maroua, PO Box 46, Maroua, Cameroon.
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19
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Plumridge A, Meisburger SP, Andresen K, Pollack L. The impact of base stacking on the conformations and electrostatics of single-stranded DNA. Nucleic Acids Res 2017; 45:3932-3943. [PMID: 28334825 PMCID: PMC5397193 DOI: 10.1093/nar/gkx140] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/17/2017] [Indexed: 12/17/2022] Open
Abstract
Single-stranded DNA (ssDNA) is notable for its interactions with ssDNA binding proteins (SSBs) during fundamentally important biological processes including DNA repair and replication. Previous work has begun to characterize the conformational and electrostatic properties of ssDNA in association with SSBs. However, the conformational distributions of free ssDNA have been difficult to determine. To capture the vast array of ssDNA conformations in solution, we pair small angle X-ray scattering with novel ensemble fitting methods, obtaining key parameters such as the size, shape and stacking character of strands with different sequences. Complementary ion counting measurements using inductively coupled plasma atomic emission spectroscopy are employed to determine the composition of the ion atmosphere at physiological ionic strength. Applying this combined approach to poly dA and poly dT, we find that the global properties of these sequences are very similar, despite having vastly different propensities for single-stranded helical stacking. These results suggest that a relatively simple mechanism for the binding of ssDNA to non-specific SSBs may be at play, which explains the disparity in binding affinities observed for these systems.
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Affiliation(s)
- Alex Plumridge
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | | | - Kurt Andresen
- Department of Physics, Gettysburg College, Gettysburg, PA 17325, USA
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
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20
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Clay MC, Ganser LR, Merriman DK, Al-Hashimi HM. Resolving sugar puckers in RNA excited states exposes slow modes of repuckering dynamics. Nucleic Acids Res 2017; 45:e134. [PMID: 28609788 PMCID: PMC5737546 DOI: 10.1093/nar/gkx525] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/01/2017] [Accepted: 06/05/2017] [Indexed: 11/15/2022] Open
Abstract
Recent studies have shown that RNAs exist in dynamic equilibrium with short-lived low-abundance 'excited states' that form by reshuffling base pairs in and around non-canonical motifs. These conformational states are proposed to be rich in non-canonical motifs and to play roles in the folding and regulatory functions of non-coding RNAs but their structure proves difficult to characterize given their transient nature. Here, we describe an approach for determining sugar pucker conformation in RNA excited states through nuclear magnetic resonance measurements of C1΄ and C4΄ rotating frame spin relaxation (R1ρ) in uniformly 13C/15N labeled RNA samples. Application to HIV-1 TAR exposed slow modes of sugar repuckering dynamics at the μs and ms timescale accompanying transitions between non-helical (C2΄-endo) to helical (C3΄-endo) conformations during formation of two distinct excited states. In contrast, we did not obtain any evidence for slow sugar repuckering dynamics for nucleotides in a variety of structural contexts that do not undergo non-helical to helical transitions. Our results outline a route for significantly improving the conformational characterization of RNA excited states and suggest that slow modes of repuckering dynamics gated by transient changes in secondary structure are quite common in RNA.
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Affiliation(s)
- Mary C. Clay
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Laura R. Ganser
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Hashim M. Al-Hashimi
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
- Department of Chemistry, Duke University, Durham, NC 27708, USA
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21
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Plumridge A, Meisburger SP, Pollack L. Visualizing single-stranded nucleic acids in solution. Nucleic Acids Res 2017; 45:e66. [PMID: 28034955 PMCID: PMC5435967 DOI: 10.1093/nar/gkw1297] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 12/09/2016] [Accepted: 12/13/2016] [Indexed: 02/06/2023] Open
Abstract
Single-stranded nucleic acids (ssNAs) are ubiquitous in many key cellular functions. Their flexibility limits both the number of high-resolution structures available, leaving only a small number of protein-ssNA crystal structures, while forcing solution investigations to report ensemble averages. A description of the conformational distributions of ssNAs is essential to more fully characterize biologically relevant interactions. We combine small angle X-ray scattering (SAXS) with ensemble-optimization methods (EOM) to dynamically build and refine sets of ssNA structures. By constructing candidate chains in representative dinucleotide steps and refining the models against SAXS data, a broad array of structures can be obtained to match varying solution conditions and strand sequences. In addition to the distribution of large scale structural parameters, this approach reveals, for the first time, intricate details of the phosphate backbone and underlying strand conformations. Such information on unperturbed strands will critically inform a detailed understanding of an array of problems including protein-ssNA binding, RNA folding and the polymer nature of NAs. In addition, this scheme, which couples EOM selection with an iteratively refining pool to give confidence in the underlying structures, is likely extendable to the study of other flexible systems.
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Affiliation(s)
- Alex Plumridge
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | | | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
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22
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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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23
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Borkar AN, Vallurupalli P, Camilloni C, Kay LE, Vendruscolo M. Simultaneous NMR characterisation of multiple minima in the free energy landscape of an RNA UUCG tetraloop. Phys Chem Chem Phys 2017; 19:2797-2804. [PMID: 28067358 PMCID: PMC6529357 DOI: 10.1039/c6cp08313g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
RNA molecules in solution tend to undergo structural fluctuations of relatively large amplitude and to populate a range of different conformations some of which with low populations. It is still very challenging, however, to characterise the structures of these low populated states and to understand their functional roles. In the present study, we address this problem by using NMR residual dipolar couplings (RDCs) as structural restraints in replica-averaged metadynamics (RAM) simulations. By applying this approach to a 14-mer RNA hairpin containing the prototypical UUCG tetraloop motif, we show that it is possible to construct the free energy landscape of this RNA molecule. This free energy landscapes reveals the surprisingly rich dynamics of the UUCG tetraloop and identifies the multiple substates that exist in equilibrium owing to thermal fluctuations. The approach that we present is general and can be applied to the study of the free energy landscapes of other RNA or RNA-protein systems.
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Affiliation(s)
- Aditi N Borkar
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
| | - Pramodh Vallurupalli
- Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Canada M5S 1A8
| | - Carlo Camilloni
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Canada M5S 1A8
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24
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Fukal J, Páv O, Buděšínský M, Šebera J, Sychrovský V. The benchmark of 31P NMR parameters in phosphate: a case study on structurally constrained and flexible phosphate. Phys Chem Chem Phys 2017; 19:31830-31841. [DOI: 10.1039/c7cp06969c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A benchmark for structural interpretation of the 31P NMR shift and the 2JP,C spin–spin coupling in the phosphate group was obtained by means of theoretical calculations and measurements in diethylphosphate and 5,5-dimethyl-2-hydroxy-1,3,2-dioxaphosphinane 2-oxide.
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Affiliation(s)
- Jiří Fukal
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- Praha 6
- Czech Republic
| | - Ondřej Páv
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- Praha 6
- Czech Republic
| | - Miloš Buděšínský
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- Praha 6
- Czech Republic
| | - Jakub Šebera
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- Praha 6
- Czech Republic
| | - Vladimír Sychrovský
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- Praha 6
- Czech Republic
- Department of Electrotechnology
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25
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Abstract
Interactions between protein and RNA play a key role in many biological processes in the gene expression pathway. Those interactions are mediated through a variety of RNA-binding protein domains, among them the highly abundant RNA recognition motif (RRM). Here we studied protein-RNA complexes from different RNA binding domain families solved by NMR and x-ray crystallography. Characterizing the structural properties of the RNA at the binding interfaces revealed an unexpected number of nucleotides with unusual RNA conformations, specifically found in RNA-RRM complexes. Moreover, we observed that the RNA nucleotides that are directly involved in interactions with the RRM domains, via hydrogen bonds and hydrophobic contacts, are significantly enriched with unique RNA conformations. Further examination of the sequences binding the RRM domain showed a preference for G nucleotides in syn conformation to precede or to follow U nucleotides in the anti-conformation, and U nucleotides in C2' endo conformation to precede U and G nucleotides possessing the more common C3' endo conformation. These findings imply a possible mode of RNA recognition by the RRM domains which enables the recognition of a wide variety of different RNA sequences and shapes. Overall, this study suggests an additional way by which the RRM domain recognizes its RNA target, involving a conformational readout.
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Affiliation(s)
- Efrat Kligun
- a Department of Biology; Technion - Israel Institute of Technology ; Haifa , Israel
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26
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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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27
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Havrila M, Zgarbová M, Jurečka P, Banáš P, Krepl M, Otyepka M, Šponer J. Microsecond-Scale MD Simulations of HIV-1 DIS Kissing-Loop Complexes Predict Bulged-In Conformation of the Bulged Bases and Reveal Interesting Differences between Available Variants of the AMBER RNA Force Fields. J Phys Chem B 2015; 119:15176-90. [DOI: 10.1021/acs.jpcb.5b08876] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marek Havrila
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, 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
| | - 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
| | - 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
| | - Miroslav Krepl
- 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
| | - 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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28
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Zhu Q, Liu G, Kai M. DNA Aptamers in the Diagnosis and Treatment of Human Diseases. Molecules 2015; 20:20979-97. [PMID: 26610462 PMCID: PMC6332121 DOI: 10.3390/molecules201219739] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/16/2015] [Accepted: 11/16/2015] [Indexed: 02/07/2023] Open
Abstract
Aptamers have a promising role in the field of life science and have been extensively researched for application as analytical tools, therapeutic agents and as vehicles for targeted drug delivery. Compared with RNA aptamers, DNA aptamers have inherent advantages in stability and facility of generation and synthesis. To better understand the specific potential of DNA aptamers, an overview of the progress in the generation and application of DNA aptamers in human disease diagnosis and therapy are presented in this review. Special attention is given to researches that are relatively close to practical application. DNA aptamers are expected to have great potential in the diagnosis and treatment of human diseases.
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Affiliation(s)
- Qinchang Zhu
- Faculty of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
| | - Ge Liu
- Department of Genomic Epidemiology, Research Center for Environment and Developmental Medical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan.
| | - Masaaki Kai
- Faculty of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
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29
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Shruthi Sureshan C, Habeeb SKM. Identification and conformational analysis of putative microRNAs in Maruca vitrata (Lepidoptera: Pyralidae). Appl Transl Genom 2015; 7:2-12. [PMID: 27054079 PMCID: PMC4803788 DOI: 10.1016/j.atg.2015.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/21/2015] [Accepted: 10/14/2015] [Indexed: 11/29/2022]
Abstract
MicroRNAs (miRNAs) are a class of small RNAs, evolutionarily conserved endogenous non-coding RNAs that regulate their target mRNA expression by either inactivating or degrading mRNA genes; thus playing an important role in the growth and development of an organism. Maruca vitrata is an insect pest of leguminous plants like pigeon pea, cowpea and mung bean and is pantropical. In this study, we perform BLAST on all known miRNAs against the transcriptome data of M. vitrata and thirteen miRNAs were identified. These miRNAs were characterised and their target genes were identified using TargetScan and were functionally annotated using FlyBase. The importance of the structure of pre-miRNA in the Drosha activity led to study the backbone torsion angles of predicted pre-miRNAs (mvi-miR-9751, mvi-miR-649-3p, mvi-miR-4057 and mvi-miR-1271) to identify various nucleotide triplets that contribute to the variation of torsion angle values at various structural motifs of a pre-miRNA.
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Affiliation(s)
- C Shruthi Sureshan
- Department of Bioinformatics, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - S K M Habeeb
- Department of Bioinformatics, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
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30
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Andrushchenko V, Benda L, Páv O, Dračínský M, Bouř P. Vibrational Properties of the Phosphate Group Investigated by Molecular Dynamics and Density Functional Theory. J Phys Chem B 2015; 119:10682-92. [PMID: 26193890 DOI: 10.1021/acs.jpcb.5b05124] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The phosphate group (PO2(-)) is an important building block occurring in many components of living matter including nucleic acids. It provides distinct features in vibrational spectra and is useful as a local probe of NA conformation and interactions with the environment. For this purpose, it is desirable to explore in detail various factors influencing spectral shapes of characteristic phosphate vibrations. In the present study, effects of the solvent and conformational averaging are analyzed for simple model molecules, dimethylphosphate, ethylmethylphosphate, and ethylmethylthiophosphate. Infrared absorption (IR) and Raman spectra were measured and calculated using a combination of molecular dynamics (MD) and density functional theory (DFT). To fully understand the link between the structure and the spectra, the solvent has to be explicitly included in the computational modeling. The results indicate that vibrational properties of the phosphate moiety are very sensitive to its conformation and interactions with the aqueous environment indeed. Polarizable continuum solvent models without explicit water molecules provided significantly worse agreement with the experiment. The combined MD/DFT approach captures well spectral characteristics for the model systems and constitutes the most reliable basis for exploration of phosphate vibrational properties in biomolecular structural studies.
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Affiliation(s)
- Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| | - Ladislav Benda
- Institute of Organic Chemistry and Biochemistry, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| | - Ondřej Páv
- Institute of Organic Chemistry and Biochemistry, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Flemingovo náměstí 2, 16610, Prague, Czech Republic
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31
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Condon D, Kennedy SD, Mort BC, Kierzek R, Yildirim I, Turner DH. Stacking in RNA: NMR of Four Tetramers Benchmark Molecular Dynamics. J Chem Theory Comput 2015; 11:2729-2742. [PMID: 26082675 PMCID: PMC4463549 DOI: 10.1021/ct501025q] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Indexed: 12/31/2022]
Abstract
Molecular dynamics (MD) simulations for RNA tetramers r(AAAA), r(CAAU), r(GACC), and r(UUUU) are benchmarked against 1H-1H NOESY distances and 3J scalar couplings to test effects of RNA torsion parametrizations. Four different starting structures were used for r(AAAA), r(CAAU), and r(GACC), while five starting structures were used for r(UUUU). On the basis of X-ray structures, criteria are reported for quantifying stacking. The force fields, AMBER ff99, parmbsc0, parm99χ_Yil, ff10, and parmTor, all predict experimentally unobserved stacks and intercalations, e.g., base 1 stacked between bases 3 and 4, and incorrect χ, ϵ, and sugar pucker populations. The intercalated structures are particularly stable, often lasting several microseconds. Parmbsc0, parm99χ_Yil, and ff10 give similar agreement with NMR, but the best agreement is only 46%. Experimentally unobserved intercalations typically are associated with reduced solvent accessible surface area along with amino and hydroxyl hydrogen bonds to phosphate nonbridging oxygens. Results from an extensive set of MD simulations suggest that recent force field parametrizations improve predictions, but further improvements are necessary to provide reasonable agreement with NMR. In particular, intramolecular stacking and hydrogen bonding interactions may not be well balanced with the TIP3P water model. NMR data and the scoring method presented here provide rigorous benchmarks for future changes in force fields and MD methods.
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Affiliation(s)
- David
E. Condon
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Scott D. Kennedy
- Department
of Biochemistry and Biophysics, University
of Rochester, Rochester, New York 14642, United States
| | - Brendan C. Mort
- University
of Rochester Center for Integrated Research Computing, Rochester, New York 14627, United States
| | - Ryszard Kierzek
- Institute
of Bioorganic Chemistry, Polish Academy
of Sciences, 60-704 Poznan, Poland
| | - Ilyas Yildirim
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Douglas H. Turner
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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32
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Gong Z, Zhao Y, Chen C, Duan Y, Xiao Y. Insights into ligand binding to PreQ1 Riboswitch Aptamer from molecular dynamics simulations. PLoS One 2014; 9:e92247. [PMID: 24663240 PMCID: PMC3963873 DOI: 10.1371/journal.pone.0092247] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/19/2014] [Indexed: 11/19/2022] Open
Abstract
Riboswitches play roles in transcriptional or translational regulation through specific ligand binding of their aptamer domains. 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, preQ1 riboswitch aptamer domain from Bacillus subtilis is studied by overall 1.5 μs all-atom molecular dynamics simulations We found that the ligand-free aptamer has a stable state with a folded P1-L3 and open binding pocket. The latter forms a cytosine-rich pool in which the nucleotide C19 oscillates between close and open positions, making it a potential conformation for preQ1 entrance. The dynamic picture further suggests that the specific recognition of preQ1 by the aptamer domain is not only facilitated by the key nucleotide C19 but also aided and enhanced by other cytosines around the binding pocket. These results should help to understand the details of preQ1 binding.
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Affiliation(s)
- Zhou Gong
- Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yunjie Zhao
- Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Changjun Chen
- Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yong Duan
- Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Genome Center and Department of Biomedical Engineering, University of California Davis, Davis, California, United States of America
| | - Yi Xiao
- Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail:
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33
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Condon D, Yildirim I, Kennedy SD, Mort BC, Kierzek R, Turner DH. Optimization of an AMBER force field for the artificial nucleic acid, LNA, and benchmarking with NMR of L(CAAU). J Phys Chem B 2014; 118:1216-28. [PMID: 24377321 PMCID: PMC3917691 DOI: 10.1021/jp408909t] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 12/27/2013] [Indexed: 01/09/2023]
Abstract
Locked Nucleic Acids (LNAs) are RNA analogues with an O2'-C4' methylene bridge which locks the sugar into a C3'-endo conformation. This enhances hybridization to DNA and RNA, making LNAs useful in microarrays and potential therapeutics. Here, the LNA, L(CAAU), provides a simplified benchmark for testing the ability of molecular dynamics (MD) to approximate nucleic acid properties. LNA χ torsions and partial charges were parametrized to create AMBER parm99_LNA. The revisions were tested by comparing MD predictions with AMBER parm99 and parm99_LNA against a 200 ms NOESY NMR spectrum of L(CAAU). NMR indicates an A-Form equilibrium ensemble. In 3000 ns simulations starting with an A-form structure, parm99_LNA and parm99 provide 66% and 35% agreement, respectively, with NMR NOE volumes and (3)J-couplings. In simulations of L(CAAU) starting with all χ torsions in a syn conformation, only parm99_LNA is able to repair the structure. This implies methods for parametrizing force fields for nucleic acid mimics can reasonably approximate key interactions and that parm99_LNA will improve reliability of MD studies for systems with LNA. A method for approximating χ population distribution on the basis of base to sugar NOEs is also introduced.
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Affiliation(s)
- David
E. Condon
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Ilyas Yildirim
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Scott D. Kennedy
- Department
of Biochemistry and Biophysics, Univeristy
of Rochester, Rochester, New York 14642, United
States
| | - Brendan C. Mort
- University of Rochester
Center for Integrated Research Computing, Rochester, New York 14627, United States
| | - Ryszard Kierzek
- Institute
of Bioorganic Chemistry, Polish Academy
of Sciences, 61-704 Poznan, Poland
| | - Douglas H. Turner
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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Mládek A, Banáš P, Jurečka P, Otyepka M, Zgarbová M, Šponer J. Energies and 2'-Hydroxyl Group Orientations of RNA Backbone Conformations. Benchmark CCSD(T)/CBS Database, Electronic Analysis, and Assessment of DFT Methods and MD Simulations. J Chem Theory Comput 2013; 10:463-80. [PMID: 26579924 DOI: 10.1021/ct400837p] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sugar-phosphate backbone is an electronically complex molecular segment imparting RNA molecules high flexibility and architectonic heterogeneity necessary for their biological functions. The structural variability of RNA molecules is amplified by the presence of the 2'-hydroxyl group, capable of forming multitude of intra- and intermolecular interactions. Bioinformatics studies based on X-ray structure database revealed that RNA backbone samples at least 46 substates known as rotameric families. The present study provides a comprehensive analysis of RNA backbone conformational preferences and 2'-hydroxyl group orientations. First, we create a benchmark database of estimated CCSD(T)/CBS relative energies of all rotameric families and test performance of dispersion-corrected DFT-D3 methods and molecular mechanics in vacuum and in continuum solvent. The performance of the DFT-D3 methods is in general quite satisfactory. The B-LYP-D3 method provides the best trade-off between accuracy and computational demands. B3-LYP-D3 slightly outperforms the new PW6B95-D3 and MPW1B95-D3 and is the second most accurate density functional of the study. The best agreement with CCSD(T)/CBS is provided by DSD-B-LYP-D3 double-hybrid functional, although its large-scale applications may be limited by high computational costs. Molecular mechanics does not reproduce the fine energy differences between the RNA backbone substates. We also demonstrate that the differences in the magnitude of the hyperconjugation effect do not correlate with the energy ranking of the backbone conformations. Further, we investigated the 2'-hydroxyl group orientation preferences. For all families, we conducted a QM and MM hydroxyl group rigid scan in gas phase and solvent. We then carried out set of explicit solvent MD simulations of folded RNAs and analyze 2'-hydroxyl group orientations of different backbone families in MD. The solvent energy profiles determined primarily by the sugar pucker match well with the distribution data derived from the simulations. The QM and MM energy profiles predict the same 2'-hydroxyl group orientation preferences. Finally, we demonstrate that the high energy of unfavorable and rarely sampled 2'-hydroxyl group orientations can be attributed to clashes between occupied orbitals.
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Affiliation(s)
- Arnošt Mládek
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 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
| | - 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
| | - 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
| | - 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
| | - 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
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35
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Galindo-Murillo R, Bergonzo C, Cheatham TE. Molecular modeling of nucleic acid structure. ACTA ACUST UNITED AC 2013; 54:7.5.1-7.5.13. [PMID: 24510799 DOI: 10.1002/0471142700.nc0705s54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
This unit is the first in a series of four units covering the analysis of nucleic acid structure by molecular modeling. The unit provides an overview of the computer simulation of nucleic acids. Topics include the static structure model, computational graphics and energy models, the generation of an initial model, and characterization of the overall three-dimensional structure.
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Affiliation(s)
- Rodrigo Galindo-Murillo
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
| | - Christina Bergonzo
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
| | - Thomas E Cheatham
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah
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36
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Halder S, Bhattacharyya D. RNA structure and dynamics: a base pairing perspective. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 113:264-83. [PMID: 23891726 DOI: 10.1016/j.pbiomolbio.2013.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/25/2013] [Accepted: 07/16/2013] [Indexed: 12/12/2022]
Abstract
RNA is now known to possess various structural, regulatory and enzymatic functions for survival of cellular organisms. Functional RNA structures are generally created by three-dimensional organization of small structural motifs, formed by base pairing between self-complementary sequences from different parts of the RNA chain. In addition to the canonical Watson-Crick or wobble base pairs, several non-canonical base pairs are found to be crucial to the structural organization of RNA molecules. They appear within different structural motifs and are found to stabilize the molecule through long-range intra-molecular interactions between basic structural motifs like double helices and loops. These base pairs also impart functional variation to the minor groove of A-form RNA helices, thus forming anchoring site for metabolites and ligands. Non-canonical base pairs are formed by edge-to-edge hydrogen bonding interactions between the bases. A large number of theoretical studies have been done to detect and analyze these non-canonical base pairs within crystal or NMR derived structures of different functional RNA. Theoretical studies of these isolated base pairs using ab initio quantum chemical methods as well as molecular dynamics simulations of larger fragments have also established that many of these non-canonical base pairs are as stable as the canonical Watson-Crick base pairs. This review focuses on the various structural aspects of non-canonical base pairs in the organization of RNA molecules and the possible applications of these base pairs in predicting RNA structures with more accuracy.
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Affiliation(s)
- Sukanya Halder
- Biophysics division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064, India
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37
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Čech P, Kukal J, Černý J, Schneider B, Svozil D. Automatic workflow for the classification of local DNA conformations. BMC Bioinformatics 2013; 14:205. [PMID: 23800225 PMCID: PMC3694522 DOI: 10.1186/1471-2105-14-205] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 05/28/2013] [Indexed: 12/03/2022] Open
Abstract
Background A growing number of crystal and NMR structures reveals a considerable structural polymorphism of DNA architecture going well beyond the usual image of a double helical molecule. DNA is highly variable with dinucleotide steps exhibiting a substantial flexibility in a sequence-dependent manner. An analysis of the conformational space of the DNA backbone and the enhancement of our understanding of the conformational dependencies in DNA are therefore important for full comprehension of DNA structural polymorphism. Results A detailed classification of local DNA conformations based on the technique of Fourier averaging was published in our previous work. However, this procedure requires a considerable amount of manual work. To overcome this limitation we developed an automatic classification method consisting of the combination of supervised and unsupervised approaches. A proposed workflow is composed of k-NN method followed by a non-hierarchical single-pass clustering algorithm. We applied this workflow to analyze 816 X-ray and 664 NMR DNA structures released till February 2013. We identified and annotated six new conformers, and we assigned four of these conformers to two structurally important DNA families: guanine quadruplexes and Holliday (four-way) junctions. We also compared populations of the assigned conformers in the dataset of X-ray and NMR structures. Conclusions In the present work we developed a machine learning workflow for the automatic classification of dinucleotide conformations. Dinucleotides with unassigned conformations can be either classified into one of already known 24 classes or they can be flagged as unclassifiable. The proposed machine learning workflow permits identification of new classes among so far unclassifiable data, and we identified and annotated six new conformations in the X-ray structures released since our previous analysis. The results illustrate the utility of machine learning approaches in the classification of local DNA conformations.
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Affiliation(s)
- Petr Čech
- Laboratory of Informatics and Chemistry, ICT Prague, Technická 5, Prague 6, 166 28, Czech Republic
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38
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Abstract
RNA molecules have highly versatile structures that can fold into myriad conformations, providing many potential pockets for binding small molecules. The increasing number of available RNA structures, in complex with proteins, small ligands and in free form, enables the design of new therapeutically useful RNA-binding ligands. Here we studied RNA ligand complexes from 10 RNA groups extracted from the protein data bank (PDB), including adaptive and non-adaptive complexes. We analyzed the chemical, physical, structural and conformational properties of binding pockets around the ligand. Comparing the properties of ligand-binding pockets to the properties of computed pockets extracted from all available RNA structures and RNA-protein interfaces, revealed that ligand-binding pockets, mainly the adaptive pockets, are characterized by unique properties, specifically enriched in rare conformations of the nucleobase and the sugar pucker. Further, we demonstrate that nucleotides possessing the rare conformations are preferentially involved in direct interactions with the ligand. Overall, based on our comprehensive analysis of RNA-ligand complexes, we suggest that the unique conformations adopted by RNA nucleotides play an important role in RNA recognition by small ligands. We term the recognition of a binding site by a ligand via the unique RNA conformations "RNA conformational readout." We propose that "conformational readout" is a general way by which RNA binding pockets are recognized and selected from an ensemble of different RNA states.
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Affiliation(s)
- Efrat Kligun
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
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39
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Guzzo CR, Dunger G, Salinas RK, Farah CS. Structure of the PilZ-FimXEAL-c-di-GMP Complex Responsible for the Regulation of Bacterial Type IV Pilus Biogenesis. J Mol Biol 2013; 425:2174-97. [PMID: 23507310 DOI: 10.1016/j.jmb.2013.03.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 03/02/2013] [Accepted: 03/11/2013] [Indexed: 10/27/2022]
Abstract
Signal transduction pathways mediated by cyclic-bis(3'→5')-dimeric GMP (c-di-GMP) control many important and complex behaviors in bacteria. C-di-GMP is synthesized through the action of GGDEF domains that possess diguanylate cyclase activity and is degraded by EAL or HD-GYP domains with phosphodiesterase activity. There is mounting evidence that some important c-di-GMP-mediated pathways require protein-protein interactions between members of the GGDEF, EAL, HD-GYP and PilZ protein domain families. For example, interactions have been observed between PilZ and the EAL domain from FimX of Xanthomonas citri (Xac). FimX and PilZ are involved in the regulation of type IV pilus biogenesis via interactions of the latter with the hexameric PilB ATPase associated with the bacterial inner membrane. Here, we present the crystal structure of the ternary complex made up of PilZ, the FimX EAL domain (FimXEAL) and c-di-GMP. PilZ interacts principally with the lobe region and the N-terminal linker helix of the FimXEAL. These interactions involve a hydrophobic surface made up of amino acids conserved in a non-canonical family of PilZ domains that lack intrinsic c-di-GMP binding ability and strand complementation that joins β-sheets from both proteins. Interestingly, the c-di-GMP binds to isolated FimXEAL and to the PilZ-FimXEAL complex in a novel conformation encountered in c-di-GMP-protein complexes in which one of the two glycosidic bonds is in a rare syn conformation while the other adopts the more common anti conformation. The structure points to a means by which c-di-GMP and PilZ binding could be coupled to FimX and PilB conformational states.
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Affiliation(s)
- Cristiane R Guzzo
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, São Paulo SP 05508-000, Brazil; Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo SP 05508-900, Brazil
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40
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Tubbs J, Condon DE, Kennedy S, Hauser M, Bevilacqua P, Turner DH. The nuclear magnetic resonance of CCCC RNA reveals a right-handed helix, and revised parameters for AMBER force field torsions improve structural predictions from molecular dynamics. Biochemistry 2013; 52:996-1010. [PMID: 23286901 PMCID: PMC3571207 DOI: 10.1021/bi3010347] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 12/27/2012] [Indexed: 12/29/2022]
Abstract
The sequence dependence of RNA energetics is important for predicting RNA structure. Hairpins with C(n) loops are consistently less stable than hairpins with other loops, which suggests the structure of C(n) regions could be unusual in the "unfolded" state. For example, previous nuclear magnetic resonance (NMR) evidence suggested that polycytidylic acid forms a left-handed helix. In this study, UV melting experiments show that the hairpin formed by r(5'GGACCCCCGUCC) is less stable than r(5'GGACUUUUGUCC). NMR spectra for single-stranded C(4) oligonucleotide, mimicking the unfolded hairpin loop, are consistent with a right-handed A-form-like helix. Comparisons between NMR spectra and molecular dynamics (MD) simulations suggest that recent reparametrizations, parm99χ_YIL and parm99TOR, of the AMBER parm99 force field improve the agreement between structural features for C(4) determined by NMR and predicted by MD. Evidently, the force field revisions to parm99 improve the modeling of RNA energetics and therefore structure.
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Affiliation(s)
- Jason
D. Tubbs
- Department
of Chemistry, University of Rochester,
Rochester, New York 14627,
United States
- Center for
RNA Biology, University of Rochester, Rochester,
New York 14642,
United States
| | - David E. Condon
- Department
of Chemistry, University of Rochester,
Rochester, New York 14627,
United States
- Center for
RNA Biology, University of Rochester, Rochester,
New York 14642,
United States
| | - Scott
D. Kennedy
- Center for
RNA Biology, University of Rochester, Rochester,
New York 14642,
United States
- Department
of Biochemistry and
Biophysics, University of Rochester, Rochester,
New York 14642, United States
| | - Melanie Hauser
- Department of Chemistry, Buena Vista University, Storm Lake, Iowa 50588, United
States
- Department of Chemistry
and
Center for RNA Molecular Biology, The Pennsylvania State
University, University Park, Pennsylvania 16802, United
States
| | - Philip
C. Bevilacqua
- Department of Chemistry
and
Center for RNA Molecular Biology, The Pennsylvania State
University, University Park, Pennsylvania 16802, United
States
| | - Douglas H. Turner
- Department
of Chemistry, University of Rochester,
Rochester, New York 14627,
United States
- Center for
RNA Biology, University of Rochester, Rochester,
New York 14642,
United States
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41
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Toukach FV, Ananikov VP. Recent advances in computational predictions of NMR parameters for the structure elucidation of carbohydrates: methods and limitations. Chem Soc Rev 2013; 42:8376-415. [DOI: 10.1039/c3cs60073d] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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42
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Lönnberg TA. Can phosphate-branched RNA persist under physiological conditions? Chembiochem 2012; 13:2690-700. [PMID: 23255258 DOI: 10.1002/cbic.201200629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Indexed: 11/10/2022]
Abstract
A 2'-O-methyl-RNA oligonucleotide containing a single free 2'-OH group flanking a branching phosphotriester linkage was prepared as a model for phosphate-branched RNA by using an orthogonally protected dimeric phosphoramidite building block in solid-phase synthesis. The strategy allows the synthesis of phosphate-branched oligonucleotides, the three branches of which may be of any desired sequence. Hydrolytic reactions of the phosphotriester linkages in such oligonucleotides were studied at physiological pH in the presence (and absence) of various complementary oligonucleotides. The fully hybridized oligonucleotide model is an order of magnitude more stable than its single-stranded counterpart, which, in turn, is an order of magnitude more stable than its trinucleoside phosphotriester core lacking any oligonucleotide arms. Furthermore, kinked structures obtained by hybridizing the phosphate-branched oligonucleotide with partially complementary oligonucleotides are three to five times more stable than fully double-stranded ones and only approximately three times less stable than the so-called RNA X structure, which has been postulated to incorporate an RNA phosphotriester linkage. The results indicate that when the intrinsically unstable RNA phosphotriester linkage is embedded in an oligonucleotide of appropriate tertiary structure, its half-life can be at least several hours.
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43
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Abstract
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The RNA duplex, (5′GACGAGUGUCA)2, has two conformations in equilibrium. The nuclear
magnetic resonance solution structure reveals that the major conformation
of the loop, 5′GAGU/3′UGAG, is novel and contains two
unusual Watson–Crick/Hoogsteen GG pairs with G residues in
the syn conformation, two A residues stacked on each other in the
center of the helix with inverted sugars, and two bulged-out U residues.
The structure provides a benchmark for testing approaches for predicting
local RNA structure and a sequence that allows the design of a unique
arrangement of functional groups and/or a conformational switch into
nucleic acids.
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Affiliation(s)
- Scott D Kennedy
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
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44
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Šponer J, Mládek A, Šponer JE, Svozil D, Zgarbová M, Banáš P, Jurečka P, Otyepka M. The DNA and RNA sugar-phosphate backbone emerges as the key player. An overview of quantum-chemical, structural biology and simulation studies. Phys Chem Chem Phys 2012; 14:15257-77. [PMID: 23072945 DOI: 10.1039/c2cp41987d] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Knowledge of geometrical and physico-chemical properties of the sugar-phosphate backbone substantially contributes to the comprehension of the structural dynamics, function and evolution of nucleic acids. We provide a side by side overview of structural biology/bioinformatics, quantum chemical and molecular mechanical/simulation studies of the nucleic acids backbone. We highlight main features, advantages and limitations of these techniques, with a special emphasis given to their synergy. The present status of the research is then illustrated by selected examples which include classification of DNA and RNA backbone families, benchmark structure-energy quantum chemical calculations, parameterization of the dihedral space of simulation force fields, incorporation of arsenate into DNA, sugar-phosphate backbone self-cleavage in small RNA enzymes, and intricate geometries of the backbone in recurrent RNA building blocks. Although not apparent from the current literature showing limited overlaps between the QM, simulation and bioinformatics studies of the nucleic acids backbone, there in fact should be a major cooperative interaction between these three approaches in studies of the sugar-phosphate backbone.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic.
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45
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Zgarbová M, Luque FJ, Šponer J, Otyepka M, Jurečka P. A Novel Approach for Deriving Force Field Torsion Angle Parameters Accounting for Conformation-Dependent Solvation Effects. J Chem Theory Comput 2012; 8:3232-42. [DOI: 10.1021/ct3001987] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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
| | - F. Javier Luque
- Department de
Fisicoquímica
and Institut de Biomedicina (IBUB), Facultat de Farmàcia, Universitat
de Barcelona, Avgda Diagonal 643, Barcelona 08028, Spain
| | - 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
| | - 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
| | - 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
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46
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Abstract
The review will discuss the influence of metal ions on conformational changes of oligonucleotides. First, a short definition of the torsion angles is given, followed by a concise yet critical overview of the commonly applied experimental techniques. Finally, the possible role of metals upon the following conformational changes of oligonucleotides is discussed: (i) the denaturation of double-strands, (ii) the transition from B- to A-DNA, (iii) the transition from right- to left-handed DNA and RNA, (iv) the condensation, (v) and other conformational changes. We conclude with a summary and outlook.
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Affiliation(s)
- Bernhard Spingler
- Institute of Inorganic Chemistry, University of Zürich, Zürich, Switzerland.
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47
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Pavelcik F. Application of constrained real-space refinement of flexible molecular fragments to automatic model building of RNA structures. J Appl Crystallogr 2012. [DOI: 10.1107/s0021889812007546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
New methods have been developed for locating phosphate groups and nucleic acid bases in the electron density of RNA structures. These methods utilize a constrained real-space refinement of molecular fragments and a phased rotation–conformation–translation function. Real-space refinement has also contributed to the improvement of the bone/base method of RNA model building and to redesigning the method of building double helices in nucleic acid structures. This improvement is reflected in the increased accuracy of the model building and the ability to better distinguish between correct and false solutions. A program,RSR, was created, and the programsNUT,HELandDHLwere upgraded and organized into a program system, which is CCP4 oriented. Source codes will also be released.
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48
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Humphris-Narayanan E, Pyle AM. Discrete RNA libraries from pseudo-torsional space. J Mol Biol 2012; 421:6-26. [PMID: 22425640 DOI: 10.1016/j.jmb.2012.03.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 02/28/2012] [Accepted: 03/06/2012] [Indexed: 11/27/2022]
Abstract
The discovery that RNA molecules can fold into complex structures and carry out diverse cellular roles has led to interest in developing tools for modeling RNA tertiary structure. While significant progress has been made in establishing that the RNA backbone is rotameric, few libraries of discrete conformations specifically for use in RNA modeling have been validated. Here, we present six libraries of discrete RNA conformations based on a simplified pseudo-torsional notation of the RNA backbone, comparable to phi and psi in the protein backbone. We evaluate the ability of each library to represent single nucleotide backbone conformations, and we show how individual library fragments can be assembled into dinucleotides that are consistent with established RNA backbone descriptors spanning from sugar to sugar. We then use each library to build all-atom models of 20 test folds, and we show how the composition of a fragment library can limit model quality. Despite the limitations inherent in using discretized libraries, we find that several hundred discrete fragments can rebuild RNA folds up to 174 nucleotides in length with atomic-level accuracy (<1.5 Å RMSD). We anticipate that the libraries presented here could easily be incorporated into RNA structural modeling, analysis, or refinement tools.
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49
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Benda L, Sochorová Vokáčová Z, Straka M, Sychrovský V. Correlating the 31P NMR chemical shielding tensor and the 2J(P,C) spin-spin coupling constants with torsion angles ζ and α in the backbone of nucleic acids. J Phys Chem B 2012; 116:3823-33. [PMID: 22380464 DOI: 10.1021/jp2099043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Determination of nucleic acid (NA) structure with NMR spectroscopy is limited by the lack of restraints on conformation of NA phosphate. In this work, the (31)P chemical shielding tensor, the Γ(P,C5'H5'1) and Γ(P,C5'H5'2) cross-correlated relaxation rates, and the (2)J(P,C3'), (2)J(P,C5'), and (3)J(P,C4') coupling constants were calculated in dependence on NA backbone torsion angles ζ and α. While the orientation of the (31)P chemical shielding tensor was almost independent of the NA phosphate conformation, the principal tensor components varied by up to ~40 ppm. This variation and the dependence of the phosphate geometry on torsion angles ζ and α had only a minor influence on the calculated Γ(P,C5'H5'1) and Γ(P,C5'H5'2) cross-correlated relaxation rates, and therefore, the so-called rigid tensor approximation was here validated. For the first time, the (2)J(P,C) spin-spin coupling constants were correlated with the conformation of NA phosphate. Although each of the two J-couplings was significantly modulated by both torsions ζ and α, the (2)J(P,C3') coupling could be structurally assigned to torsion ζ and the (2)J(P,C5') coupling to torsion α. We propose qualitative rules for their structural interpretation as loose restraints on torsion angles ζ and α. The (3)J(P,C4') coupling assigned to torsion angle β was found dependent also on torsions ζ and α, implying that the uncertainty in determination of β with standard Karplus curves could be as large as ~25°. The calculations provided a unified picture of NMR parameters applicable for the determination of NA phosphate conformation.
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Affiliation(s)
- Ladislav Benda
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, vvi, Prague, Czech Republic.
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50
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Mládek A, Šponer JE, Kulhánek P, Lu XJ, Olson WK, Šponer J. Understanding the Sequence Preference of Recurrent RNA Building Blocks using Quantum Chemistry: The Intrastrand RNA Dinucleotide Platform. J Chem Theory Comput 2012; 8:335-347. [PMID: 22712001 PMCID: PMC3375708 DOI: 10.1021/ct200712b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Folded RNA molecules are shaped by an astonishing variety of highly conserved noncanonical molecular interactions and backbone topologies. The dinucleotide platform is a widespread recurrent RNA modular building submotif formed by the side-by-side pairing of bases from two consecutive nucleotides within a single strand, with highly specific sequence preferences. This unique arrangement of bases is cemented by an intricate network of noncanonical hydrogen bonds and facilitated by a distinctive backbone topology. The present study investigates the gas-phase intrinsic stabilities of the three most common RNA dinucleotide platforms - 5'-GpU-3', ApA, and UpC - via state-of-the-art quantum-chemical (QM) techniques. The mean stability of base-base interactions decreases with sequence in the order GpU > ApA > UpC. Bader's atoms-in-molecules analysis reveals that the N2(G)…O4(U) hydrogen bond of the GpU platform is stronger than the corresponding hydrogen bonds in the other two platforms. The mixed-pucker sugar-phosphate backbone conformation found in most GpU platforms, in which the 5'-ribose sugar (G) is in the C2'-endo form and the 3'-sugar (U) in the C3'-endo form, is intrinsically more stable than the standard A-RNA backbone arrangement, partially as a result of a favorable O2'…O2P intra-platform interaction. Our results thus validate the hypothesis of Lu et al. (Lu Xiang-Jun, et al. Nucleic Acids Res. 2010, 38, 4868-4876), that the superior stability of GpU platforms is partially mediated by the strong O2'…O2P hydrogen bond. In contrast, ApA and especially UpC platform-compatible backbone conformations are rather diverse and do not display any characteristic structural features. The average stabilities of ApA and UpC derived backbone conformers are also lower than those of GpU platforms. Thus, the observed structural and evolutionary patterns of the dinucleotide platforms can be accounted for, to a large extent, by their intrinsic properties as described by modern QM calculations. In contrast, we show that the dinucleotide platform is not properly described in the course of atomistic explicit-solvent simulations. Our work also gives methodological insights into QM calculations of experimental RNA backbone geometries. Such calculations are inherently complicated by rather large data and refinement uncertainties in the available RNA experimental structures, which often preclude reliable energy computations.
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Affiliation(s)
- Arnošt Mládek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic
| | - Judit E. 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
| | - Petr Kulhánek
- CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
| | - Xiang-Jun Lu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Wilma K. Olson
- Department of Chemistry & Chemical Biology, BioMaPS Institute for Quantitative Biology, Rutgers - The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jiřĺ 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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