1
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Oxenfarth A, Kümmerer F, Bottaro S, Schnieders R, Pinter G, Jonker HRA, Fürtig B, Richter C, Blackledge M, Lindorff-Larsen K, Schwalbe H. Integrated NMR/Molecular Dynamics Determination of the Ensemble Conformation of a Thermodynamically Stable CUUG RNA Tetraloop. J Am Chem Soc 2023. [PMID: 37479220 PMCID: PMC10401711 DOI: 10.1021/jacs.3c03578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Both experimental and theoretical structure determinations of RNAs have remained challenging due to the intrinsic dynamics of RNAs. We report here an integrated nuclear magnetic resonance/molecular dynamics (NMR/MD) structure determination approach to describe the dynamic structure of the CUUG tetraloop. We show that the tetraloop undergoes substantial dynamics, leading to averaging of the experimental data. These dynamics are particularly linked to the temperature-dependent presence of a hydrogen bond within the tetraloop. Interpreting the NMR data by a single structure represents the low-temperature structure well but fails to capture all conformational states occurring at a higher temperature. We integrate MD simulations, starting from structures of CUUG tetraloops within the Protein Data Bank, with an extensive set of NMR data, and provide a structural ensemble that describes the dynamic nature of the tetraloop and the experimental NMR data well. We thus show that one of the most stable and frequently found RNA tetraloops displays substantial dynamics, warranting such an integrated structural approach.
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Affiliation(s)
- Andreas Oxenfarth
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - Felix Kümmerer
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
- IRCCS Humanitas Research Hospital, Department of Biomedical Sciences, Humanitas University, Milan 20089, Italy
| | - Robbin Schnieders
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - György Pinter
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - Hendrik R A Jonker
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - Boris Fürtig
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - Christian Richter
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
| | - Martin Blackledge
- Institut de Biologie Structurale (IBS), CEA, CNRS, University Grenoble Alpes, Grenoble 38000, France
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Hessen, Germany
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2
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Yu B, Wang X, Wang T, Iwahara J. DNA base order parameter determination without influence of chemical exchange. Methods 2023; 210:1-9. [PMID: 36596431 PMCID: PMC9898221 DOI: 10.1016/j.ymeth.2022.12.004] [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: 10/15/2022] [Revised: 12/23/2022] [Accepted: 12/30/2022] [Indexed: 01/01/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a versatile tool used to investigate the dynamic properties of biological macromolecules and their complexes. NMR relaxation data can provide order parameters S2, which represent the mobility of bond vectors reorienting within a molecular frame. Determination of S2 parameters typically involves the use of transverse NMR relaxation rates. However, the accuracy in S2 determination can be diminished by elevation of the transverse relaxation rates through conformational or chemical exchange involving protonation/deprotonation or non-Watson-Crick base-pair states of nucleic acids. Here, we propose an approach for determination of S2 parameters without the influence of exchange processes. This approach utilizes transverse and longitudinal 13C chemical shift anisotropy (CSA) - dipole-dipole (DD) cross-correlation rates instead of 13C transverse relaxation rates. Anisotropy in rotational diffusion is taken into consideration. An application of this approach to nucleotide base CH groups of a uniformly 13C/15N-labeled DNA duplex is demonstrated.
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Affiliation(s)
- Binhan Yu
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xi Wang
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tianzhi Wang
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Junji Iwahara
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
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3
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Nam H, Becette O, LeBlanc RM, Oh D, Case DA, Dayie TK. Deleterious effects of carbon-carbon dipolar coupling on RNA NMR dynamics. JOURNAL OF BIOMOLECULAR NMR 2020; 74:321-331. [PMID: 32363430 DOI: 10.1007/s10858-020-00315-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/18/2020] [Indexed: 06/11/2023]
Abstract
Many regulatory RNAs undergo dynamic exchanges that are crucial for their biological functions and NMR spectroscopy is a versatile tool for monitoring dynamic motions of biomolecules. Meaningful information on biomolecular dynamics requires an accurate measurement of relaxation parameters such as longitudinal (R1) rates, transverse (R2) rates and heteronuclear Overhauser effect (hNOE). However, earlier studies have shown that the large 13C-13C interactions complicate analysis of the carbon relaxation parameters. To investigate the effect of 13C-13C interactions on RNA dynamic studies, we performed relaxation measurements on various RNA samples with different labeling patterns and compared these measurements with the computational simulations. For uniformly labeled samples, contributions of the neighboring carbon to R1 measurements were observed. These contributions increased with increasing magnetic field and overall correlation time ([Formula: see text]) for R1 rates, necessitating more careful analysis for uniformly labeled large RNAs. In addition, the hNOE measurements were also affected by the adjacent carbon nuclei. Unlike R1 rates, R1ρ rates showed relatively good agreement between uniformly- and site-selectively labeled samples, suggesting no dramatic effect from their attached carbon, in agreement with previous observations. Overall, having more accurate rate measurements avoids complex analysis and will be a key for interpreting 13C relaxation rates for molecular motion that can provide valuable insights into cellular molecular recognition events.
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Affiliation(s)
- Hyeyeon Nam
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | - Owen Becette
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | - Regan M LeBlanc
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Daniel Oh
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | - David A Case
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Theodore K Dayie
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA.
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4
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Bottaro S, Nichols PJ, Vögeli B, Parrinello M, Lindorff-Larsen K. Integrating NMR and simulations reveals motions in the UUCG tetraloop. Nucleic Acids Res 2020; 48:5839-5848. [PMID: 32427326 PMCID: PMC7293013 DOI: 10.1093/nar/gkaa399] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 04/03/2020] [Accepted: 05/17/2020] [Indexed: 12/21/2022] Open
Abstract
We provide an atomic-level description of the structure and dynamics of the UUCG RNA stem-loop by combining molecular dynamics simulations with experimental data. The integration of simulations with exact nuclear Overhauser enhancements data allowed us to characterize two distinct states of this molecule. The most stable conformation corresponds to the consensus three-dimensional structure. The second state is characterized by the absence of the peculiar non-Watson-Crick interactions in the loop region. By using machine learning techniques we identify a set of experimental measurements that are most sensitive to the presence of non-native states. We find that although our MD ensemble, as well as the consensus UUCG tetraloop structures, are in good agreement with experiments, there are remaining discrepancies. Together, our results show that (i) the MD simulation overstabilize a non-native loop conformation, (ii) eNOE data support its presence with a population of ≈10% and (iii) the structural interpretation of experimental data for dynamic RNAs is highly complex, even for a simple model system such as the UUCG tetraloop.
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Affiliation(s)
- Sandro Bottaro
- Atomistic Simulations Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Parker J Nichols
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Michele Parrinello
- Atomistic Simulations Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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5
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Steffen FD, Khier M, Kowerko D, Cunha RA, Börner R, Sigel RKO. Metal ions and sugar puckering balance single-molecule kinetic heterogeneity in RNA and DNA tertiary contacts. Nat Commun 2020; 11:104. [PMID: 31913262 PMCID: PMC6949254 DOI: 10.1038/s41467-019-13683-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 11/15/2019] [Indexed: 11/13/2022] Open
Abstract
The fidelity of group II intron self-splicing and retrohoming relies on long-range tertiary interactions between the intron and its flanking exons. By single-molecule FRET, we explore the binding kinetics of the most important, structurally conserved contact, the exon and intron binding site 1 (EBS1/IBS1). A comparison of RNA-RNA and RNA-DNA hybrid contacts identifies transient metal ion binding as a major source of kinetic heterogeneity which typically appears in the form of degenerate FRET states. Molecular dynamics simulations suggest a structural link between heterogeneity and the sugar conformation at the exon-intron binding interface. While Mg2+ ions lock the exon in place and give rise to long dwell times in the exon bound FRET state, sugar puckering alleviates this structural rigidity and likely promotes exon release. The interplay of sugar puckering and metal ion coordination may be an important mechanism to balance binding affinities of RNA and DNA interactions in general.
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Affiliation(s)
- Fabio D Steffen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Mokrane Khier
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Danny Kowerko
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Department of Informatics, Technical University Chemnitz, Straße der Nationen 62, 09111, Chemnitz, Germany
| | - Richard A Cunha
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Richard Börner
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- Laserinstitut Hochschule Mittweida, University of Applied Sciences Mittweida, Technikumplatz 17, 09648, Mittweida, Germany.
| | - Roland K O Sigel
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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6
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Cetiner EC, Jonker HRA, Helmling C, Gophane DB, Grünewald C, Sigurdsson ST, Schwalbe H. Paramagnetic-iterative relaxation matrix approach: extracting PRE-restraints from NOESY spectra for 3D structure elucidation of biomolecules. JOURNAL OF BIOMOLECULAR NMR 2019; 73:699-712. [PMID: 31606877 DOI: 10.1007/s10858-019-00282-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/27/2019] [Indexed: 06/10/2023]
Abstract
Paramagnetic relaxation enhancement (PRE) can be used to determine long-range distance restraints in biomolecules. The PREs are typically determined by analysis of intensity differences in HSQC experiments of paramagnetic and diamagnetic spin labels. However, this approach requires both isotope- and spin-labelling. Herein, we report a novel method to evaluate NOESY intensities in the presence of a paramagnetic moiety to determine PRE restraints. The advantage of our approach over HSQC-based approaches is the increased number of available signals without the need for isotope labelling. NOESY intensities affected by a paramagnetic center were evaluated during a structure calculation within the paramagnetic iterative relaxation matrix approach (P-IRMA). We applied P-IRMA to a 14-mer RNA with a known NMR solution structure, which allowed us to assess the quality of the PRE restraints. To this end, three different spin labels have been attached at different positions of the 14-mer to test the influence of flexibility on the structure calculation. Structural disturbances introduced by the spin label have been evaluated by chemical shift analysis. Furthermore, the impact of P-IRMA on the quality of the structure bundles were tested by intentionally leaving out available diamagnetic restraints. Our analyses show that P-IRMA is a powerful tool to refine RNA structures for systems that are insufficiently described by using only diamagnetic restraints.
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Affiliation(s)
- E C Cetiner
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz, Goethe Universität Frankfurt am Main, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - H R A Jonker
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz, Goethe Universität Frankfurt am Main, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - C Helmling
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz, Goethe Universität Frankfurt am Main, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - D B Gophane
- Department of Chemistry Science Institute, University of Iceland, Dunhaga 3, 107, Reykjavik, Iceland
| | - C Grünewald
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz, Goethe Universität Frankfurt am Main, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany
| | - S Th Sigurdsson
- Department of Chemistry Science Institute, University of Iceland, Dunhaga 3, 107, Reykjavik, Iceland
| | - H Schwalbe
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz, Goethe Universität Frankfurt am Main, Max-von-Laue Straße 7, 60438, Frankfurt am Main, Germany.
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7
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Refining RNA solution structures with the integrative use of label-free paramagnetic relaxation enhancement NMR. BIOPHYSICS REPORTS 2019. [DOI: 10.1007/s41048-019-00099-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
AbstractNMR structure calculation is inherently integrative, and can incorporate new experimental data as restraints. As RNAs have lower proton densities and are more conformational heterogenous than proteins, the refinement of RNA structures can benefit from additional types of restraints. Paramagnetic relaxation enhancement (PRE) provides distance information between a paramagnetic probe and protein or RNA nuclei. However, covalent conjugation of a paramagnetic probe is difficult for RNAs, thus limiting the use of PRE NMR for RNA structure characterization. Here, we show that the solvent PRE can be accurately measured for RNA labile imino protons, simply with the addition of an inert paramagnetic cosolute. Demonstrated on three RNAs that have increasingly complex topologies, we show that the incorporation of the solvent PRE restraints can significantly improve the precision and accuracy of RNA structures. Importantly, the solvent PRE data can be collected for RNAs without isotope enrichment. Thus, the solvent PRE method can work integratively with other biophysical techniques for better characterization of RNA structures.
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8
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Abstract
Many of the functions of biomacromolecules can be rationalized by the characterization of their conformational energy landscapes: the structures of the dominant states, transitions between states and motions within states. Nuclear magnetic resonance (NMR) spectroscopy is the technique of choice to study internal motions in proteins. The determination of motions on picosecond to nanosecond timescales requires the measurement of nuclear spin relaxation rates at multiple magnetic fields. High sensitivity and resolution are obtained only at high magnetic fields, so that, until recently, site-specific relaxation rates in biomolecules were only measured over a narrow range of high magnetic fields. This limitation was particularly striking for the quantification of motions on nanosecond timescales, close to the correlation time for overall rotational diffusion. High-resolution relaxometry is an emerging technique to investigate picosecond-nanosecond motions of proteins. This approach uses a high-field NMR spectrometer equipped with a sample shuttle device, which allows for the measurement of the relaxation rate constants at low magnetic fields, while preserving the sensitivity and resolution of a high-field NMR spectrometer. The combined analysis of high-resolution relaxometry and standard high-field relaxation data provides a more accurate description of the dynamics of proteins, in particular in the nanosecond range. The purpose of this chapter is to describe how to perform high-resolution relaxometry experiments and how to analyze the rates measured with this technique.
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9
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Šponer J, Bussi G, Krepl M, Banáš P, Bottaro S, Cunha RA, Gil-Ley A, Pinamonti G, Poblete S, Jurečka P, Walter NG, Otyepka M. RNA Structural Dynamics As Captured by Molecular Simulations: A Comprehensive Overview. Chem Rev 2018; 118:4177-4338. [PMID: 29297679 PMCID: PMC5920944 DOI: 10.1021/acs.chemrev.7b00427] [Citation(s) in RCA: 327] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Indexed: 12/14/2022]
Abstract
With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Department of Biology , University of Copenhagen , Copenhagen 2200 , Denmark
| | - Richard A Cunha
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Giovanni Pinamonti
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Simón Poblete
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
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10
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Choi YJ, Gibala KS, Ayele T, Deventer KV, Resendiz MJE. Biophysical properties, thermal stability and functional impact of 8-oxo-7,8-dihydroguanine on oligonucleotides of RNA-a study of duplex, hairpins and the aptamer for preQ1 as models. Nucleic Acids Res 2017; 45:2099-2111. [PMID: 28426093 PMCID: PMC5389535 DOI: 10.1093/nar/gkw885] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/22/2016] [Indexed: 01/12/2023] Open
Abstract
A better understanding of the effects that oxidative lesions have on RNA is of importance to understand their role in the development/progression of disease. 8-oxo-7,8-dihydroguanine was incorporated into RNA to understand its structural and functional impact on RNA:RNA and RNA:DNA duplexes, hairpins and pseudoknots. One to three modifications were incorporated into dodecamers of RNA [AAGAGGGAUGAC] resulting in thermal destabilization (ΔTm – 10°C per lesion). Hairpins with tetraloops c-UUCG*-g* (8-10), a-ACCG-g* (11-12), c-UUG*G*-g* (13-16) and c-ACG*G*-g* (17-20) were modified and used to determine thermal stabilities, concluding that: (i) modifying the stem leads to destabilization unless adenosine is the opposing basepair of 8-oxoGua; (ii) modification at the loop is position- and sequence-dependent and varies from slight stabilization to large destabilization, in some cases leading to formation of other secondary structures (hairpin→duplex). Functional effects were established using the aptamer for preQ1 as model. Modification at G5 disrupted the stem P1 and inhibited recognition of the target molecule 7-methylamino-7-deazaguanine (preQ1). Modifying G11 results in increased thermal stability, albeit with a Kd 4-fold larger than its canonical analog. These studies show the capability of 8-oxoG to affect structure and function of RNA, resulting in distinct outcomes as a function of number and position of the lesion.
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Affiliation(s)
- Yu J Choi
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Krzysztof S Gibala
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Tewoderos Ayele
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Katherine V Deventer
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
| | - Marino J E Resendiz
- Department of Chemistry, University of Colorado Denver, Science Building 1151 Arapahoe St, Denver, CO 80204, USA
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11
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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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12
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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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13
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Kadeřávek P, Zapletal V, Fiala R, Srb P, Padrta P, Přecechtělová JP, Šoltésová M, Kowalewski J, Widmalm G, Chmelík J, Sklenář V, Žídek L. Spectral density mapping at multiple magnetic fields suitable for (13)C NMR relaxation studies. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 266:23-40. [PMID: 27003380 DOI: 10.1016/j.jmr.2016.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/20/2016] [Accepted: 02/23/2016] [Indexed: 06/05/2023]
Abstract
Standard spectral density mapping protocols, well suited for the analysis of (15)N relaxation rates, introduce significant systematic errors when applied to (13)C relaxation data, especially if the dynamics is dominated by motions with short correlation times (small molecules, dynamic residues of macromolecules). A possibility to improve the accuracy by employing cross-correlated relaxation rates and on measurements taken at several magnetic fields has been examined. A suite of protocols for analyzing such data has been developed and their performance tested. Applicability of the proposed protocols is documented in two case studies, spectral density mapping of a uniformly labeled RNA hairpin and of a selectively labeled disaccharide exhibiting highly anisotropic tumbling. Combination of auto- and cross-correlated relaxation data acquired at three magnetic fields was applied in the former case in order to separate effects of fast motions and conformational or chemical exchange. An approach using auto-correlated relaxation rates acquired at five magnetic fields, applicable to anisotropically moving molecules, was used in the latter case. The results were compared with a more advanced analysis of data obtained by interpolation of auto-correlated relaxation rates measured at seven magnetic fields, and with the spectral density mapping of cross-correlated relaxation rates. The results showed that sufficiently accurate values of auto- and cross-correlated spectral density functions at zero and (13)C frequencies can be obtained from data acquired at three magnetic fields for uniformly (13)C-labeled molecules with a moderate anisotropy of the rotational diffusion tensor. Analysis of auto-correlated relaxation rates at five magnetic fields represents an alternative for molecules undergoing highly anisotropic motions.
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Affiliation(s)
- Pavel Kadeřávek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Institute of Biophysics of Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic.
| | - Vojtěch Zapletal
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Radovan Fiala
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Pavel Srb
- Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Petr Padrta
- Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | | | - Mária Šoltésová
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, CZ-180 00 Prague, Czech Republic.
| | - Jozef Kowalewski
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
| | - Göran Widmalm
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
| | - Josef Chmelík
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, CZ-142 00 Prague 4 - Krč, Czech Republic.
| | - Vladimír Sklenář
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Lukáš Žídek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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14
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Villa A, Stock G. What NMR Relaxation Can Tell Us about the Internal Motion of an RNA Hairpin: A Molecular Dynamics Simulation Study. J Chem Theory Comput 2015; 2:1228-36. [PMID: 26626832 DOI: 10.1021/ct600160z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Classical molecular dynamics simulations of a 14-mer UUCG RNA hairpin are performed to study its conformational dynamics and corresponding NMR relaxation parameters. The direct calculation of the relaxation rates from the trajectory yields good agreement with experiment, indicating the validity of the theoretical model. Various ways to provide a link between theory and experiment are considered, including the "model-free approach" of Lipari and Szabo and Gaussian axial fluctuation model of Brüschweilwer. It is studied if the underlying assumptions of these approaches are satisfied in the case of a flexible RNA hairpin. Being consistent with the analysis of the NMR experiments, Lipari-Szabo fits of the first 100 or 1000 ps of the internal correlation functions lead to a nice agreement between calculated and experimental order parameters and internal correlation times. Finally, the relation between NMR order parameters and the underlying internal motion of the RNA hairpin is discussed in detail. A principal component analysis reveals that the principal motions of the molecule account only partially for the measured NMR order parameters, because the latter are insensitive to internal dynamics occurring on a nanosecond time scale due to molecular tumbling.
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Affiliation(s)
- Alessandra Villa
- Institute for Physical and Theoretical Chemistry, J. W. Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Gerhard Stock
- Institute for Physical and Theoretical Chemistry, J. W. Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
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15
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Salmon L, Giambaşu GM, Nikolova EN, Petzold K, Bhattacharya A, Case DA, Al-Hashimi HM. Modulating RNA Alignment Using Directional Dynamic Kinks: Application in Determining an Atomic-Resolution Ensemble for a Hairpin using NMR Residual Dipolar Couplings. J Am Chem Soc 2015; 137:12954-65. [PMID: 26306428 PMCID: PMC4748170 DOI: 10.1021/jacs.5b07229] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Approaches that combine experimental data and computational molecular dynamics (MD) to determine atomic resolution ensembles of biomolecules require the measurement of abundant experimental data. NMR residual dipolar couplings (RDCs) carry rich dynamics information, however, difficulties in modulating overall alignment of nucleic acids have limited the ability to fully extract this information. We present a strategy for modulating RNA alignment that is based on introducing variable dynamic kinks in terminal helices. With this strategy, we measured seven sets of RDCs in a cUUCGg apical loop and used this rich data set to test the accuracy of an 0.8 μs MD simulation computed using the Amber ff10 force field as well as to determine an atomic resolution ensemble. The MD-generated ensemble quantitatively reproduces the measured RDCs, but selection of a sub-ensemble was required to satisfy the RDCs within error. The largest discrepancies between the RDC-selected and MD-generated ensembles are observed for the most flexible loop residues and backbone angles connecting the loop to the helix, with the RDC-selected ensemble resulting in more uniform dynamics. Comparison of the RDC-selected ensemble with NMR spin relaxation data suggests that the dynamics occurs on the ps-ns time scales as verified by measurements of R(1ρ) relaxation-dispersion data. The RDC-satisfying ensemble samples many conformations adopted by the hairpin in crystal structures indicating that intrinsic plasticity may play important roles in conformational adaptation. The approach presented here can be applied to test nucleic acid force fields and to characterize dynamics in diverse RNA motifs at atomic resolution.
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Affiliation(s)
- Loïc Salmon
- Department of Molecular, Cellular, and Developmental Biology and Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - George M. Giambaşu
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Evgenia N. Nikolova
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Katja Petzold
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | | | - David A. Case
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Hashim M. Al-Hashimi
- Department of Biochemistry and Chemistry, Duke University School of Medicine, Durham, North Carolina, USA
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16
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Giambaşu GM, York DM, Case DA. Structural fidelity and NMR relaxation analysis in a prototype RNA hairpin. RNA (NEW YORK, N.Y.) 2015; 21:963-74. [PMID: 25805858 PMCID: PMC4408802 DOI: 10.1261/rna.047357.114] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 01/17/2015] [Indexed: 05/16/2023]
Abstract
RNA hairpins are widespread and very stable motifs that contribute decisively to RNA folding and biological function. The GTP1G2C3A4C5U6U7C8G9G10U11G12C13C14 construct (with a central UUCG tetraloop) has been extensively studied by solution NMR, and offers and excellent opportunity to evaluate the structure and dynamical description afforded by molecular dynamics (MD) simulations. Here, we compare average structural parameters and NMR relaxation rates estimated from a series of multiple independent explicit solvent MD simulations using the two most recent RNA AMBER force fields (ff99 and ff10). Predicted overall tumbling times are ∼20% faster than those inferred from analysis of NMR data and follow the same trend when temperature and ionic strength is varied. The Watson-Crick stem and the "canonical" UUCG loop structure are maintained in most simulations including the characteristic syn conformation along the glycosidic bond of G9, although some key hydrogen bonds in the loop are partially disrupted. Our analysis pinpoints G9-G10 backbone conformations as a locus of discrepancies between experiment and simulation. In general the results for the more recent force-field parameters (ff10) are closer to experiment than those for the older ones (ff99). This work provides a comprehensive and detailed comparison of state of the art MD simulations against a wide variety of solution NMR measurements.
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Affiliation(s)
- George M Giambaşu
- BioMaPS Institute for Quantitative Biology and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Darrin M York
- BioMaPS Institute for Quantitative Biology and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - David A Case
- BioMaPS Institute for Quantitative Biology and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
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17
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Berlin K, Longhini A, Dayie TK, Fushman D. Deriving quantitative dynamics information for proteins and RNAs using ROTDIF with a graphical user interface. JOURNAL OF BIOMOLECULAR NMR 2013; 57:333-352. [PMID: 24170368 PMCID: PMC3939081 DOI: 10.1007/s10858-013-9791-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/11/2013] [Indexed: 05/28/2023]
Abstract
To facilitate rigorous analysis of molecular motions in proteins, DNA, and RNA, we present a new version of ROTDIF, a program for determining the overall rotational diffusion tensor from single- or multiple-field nuclear magnetic resonance relaxation data. We introduce four major features that expand the program's versatility and usability. The first feature is the ability to analyze, separately or together, (13)C and/or (15)N relaxation data collected at a single or multiple fields. A significant improvement in the accuracy compared to direct analysis of R2/R1 ratios, especially critical for analysis of (13)C relaxation data, is achieved by subtracting high-frequency contributions to relaxation rates. The second new feature is an improved method for computing the rotational diffusion tensor in the presence of biased errors, such as large conformational exchange contributions, that significantly enhances the accuracy of the computation. The third new feature is the integration of the domain alignment and docking module for relaxation-based structure determination of multi-domain systems. Finally, to improve accessibility to all the program features, we introduced a graphical user interface that simplifies and speeds up the analysis of the data. Written in Java, the new ROTDIF can run on virtually any computer platform. In addition, the new ROTDIF achieves an order of magnitude speedup over the previous version by implementing a more efficient deterministic minimization algorithm. We not only demonstrate the improvement in accuracy and speed of the new algorithm for synthetic and experimental (13)C and (15)N relaxation data for several proteins and nucleic acids, but also show that careful analysis required especially for characterizing RNA dynamics allowed us to uncover subtle conformational changes in RNA as a function of temperature that were opaque to previous analysis.
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Affiliation(s)
- Konstantin Berlin
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
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18
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Nikolova EN, Bascom GD, Andricioaei I, Al-Hashimi HM. Probing sequence-specific DNA flexibility in a-tracts and pyrimidine-purine steps by nuclear magnetic resonance (13)C relaxation and molecular dynamics simulations. Biochemistry 2012; 51:8654-64. [PMID: 23035755 DOI: 10.1021/bi3009517] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sequence-specific DNA flexibility plays a key role in a variety of cellular interactions that are critical for gene packaging, expression, and regulation, yet few studies have experimentally explored the sequence dependence of DNA dynamics that occur on biologically relevant time scales. Here, we use nuclear magnetic resonance (NMR) carbon spin relaxation combined with molecular dynamics (MD) simulations to examine the picosecond to nanosecond dynamics in a variety of dinucleotide steps as well as in varying length homopolymeric A(n)·T(n) repeats (A(n)-tracts, where n = 2, 4, or 6) that exhibit unusual structural and mechanical properties. We extend the NMR spin relaxation time scale sensitivity deeper into the nanosecond regime by using glycerol and a longer DNA duplex to slow overall tumbling. Our studies reveal a structurally unique A-tract core (for n > 3) that is uniformly rigid, flanked by junction steps that show increasing sugar flexibility with A-tract length. High sugar mobility is observed at pyrimidine residues at the A-tract junctions, which is encoded at the dinucleotide level (CA, TG, and CG steps) and increases with A-tract length. The MD simulations reproduce many of these trends, particularly the overall rigidity of A-tract base and sugar sites, and suggest that the sugar-backbone dynamics could involve transitions in sugar pucker and phosphate backbone BI ↔ BII equilibria. Our results reinforce an emerging view that sequence-specific DNA flexibility can be imprinted in dynamics occurring deep within the nanosecond time regime that is difficult to characterize experimentally at the atomic level. Such large-amplitude sequence-dependent backbone fluctuations might flag the genome for specific DNA recognition.
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Affiliation(s)
- Evgenia N Nikolova
- Department of Chemistry and Biophysics, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA
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19
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Briggs BN, Gaier AJ, Fanwick PE, Dogutan DK, McMillin DR. Cationic Copper(II) Porphyrins Intercalate into Domains of Double-Stranded RNA. Biochemistry 2012; 51:7496-505. [PMID: 22947040 DOI: 10.1021/bi300828z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Breeze N. Briggs
- Purdue University, 560 Oval Drive, West
Lafayette, Indiana 47907, United States
| | - Abby J. Gaier
- Purdue University, 560 Oval Drive, West
Lafayette, Indiana 47907, United States
| | - Phillip E. Fanwick
- Purdue University, 560 Oval Drive, West
Lafayette, Indiana 47907, United States
| | - Dilek K. Dogutan
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts
02139, United States
| | - David R. McMillin
- Purdue University, 560 Oval Drive, West
Lafayette, Indiana 47907, United States
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20
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Bazzi A, Zargarian L, Chaminade F, De Rocquigny H, René B, Mély Y, Fossé P, Mauffret O. Intrinsic nucleic acid dynamics modulates HIV-1 nucleocapsid protein binding to its targets. PLoS One 2012; 7:e38905. [PMID: 22745685 PMCID: PMC3380039 DOI: 10.1371/journal.pone.0038905] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 05/14/2012] [Indexed: 11/19/2022] Open
Abstract
HIV-1 nucleocapsid protein (NC) is involved in the rearrangement of nucleic acids occurring in key steps of reverse transcription. The protein, through its two zinc fingers, interacts preferentially with unpaired guanines in single-stranded sequences. In mini-cTAR stem-loop, which corresponds to the top half of the cDNA copy of the transactivation response element of the HIV-1 genome, NC was found to exhibit a clear preference for the TGG sequence at the bottom of mini-cTAR stem. To further understand how this site was selected among several potential binding sites containing unpaired guanines, we probed the intrinsic dynamics of mini-cTAR using (13)C relaxation measurements. Results of spin relaxation time measurements have been analyzed using the model-free formalism and completed by dispersion relaxation measurements. Our data indicate that the preferentially recognized guanine in the lower part of the stem is exempt of conformational exchange and highly mobile. In contrast, the unrecognized unpaired guanines of mini-cTAR are involved in conformational exchange, probably related to transient base-pairs. These findings support the notion that NC preferentially recognizes unpaired guanines exhibiting a high degree of mobility. The ability of NC to discriminate between close sequences through their dynamic properties contributes to understanding how NC recognizes specific sites within the HIV genome.
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Affiliation(s)
- Ali Bazzi
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
| | - Loussiné Zargarian
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
| | - Françoise Chaminade
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
| | - Hugues De Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, Centre National de la Recherche Scientifique Unité mixte de Recherche 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Brigitte René
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, Centre National de la Recherche Scientifique Unité mixte de Recherche 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Philippe Fossé
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
| | - Olivier Mauffret
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Cachan, France
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21
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Rinnenthal J, Buck J, Ferner J, Wacker A, FÜrtig B, Schwalbe H. Mapping the landscape of RNA dynamics with NMR spectroscopy. Acc Chem Res 2011; 44:1292-301. [PMID: 21894962 DOI: 10.1021/ar200137d] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Among the three major classes of biomacromolecules (DNA, RNA, and proteins) RNA's pronounced dynamics are the most explicitly linked to its wide variety of functions, which include catalysis and the regulation of transcription, translation, and splicing. These functions are mediated by a range of RNA biomachinery, including such varied examples as macromolecular noncoding RNAs, microRNAs, small interfering RNAs, riboswitch RNAs, and RNA thermometers. In each case, the functional dynamics of an interconversion is characterized by an associated rate constant. In this Account, we provide an introduction to NMR spectroscopic characterization of the landscape of RNA dynamics. We introduce strategies for measuring NMR parameters at various time scales as well as the underlying models for describing the corresponding rate constants. RNA exhibits significant dynamic motion, which can be modulated by (i) intermolecular interactions, including specific and nonspecific binding of ions (such as Mg(2+) and tertiary amines), (ii) metabolites in riboswitches or RNA aptamers, and (iii) macromolecular interactions within ribonucleic protein particles, including the ribosome and the spliceosome. Our understanding of the nature of these dynamic changes in RNA targets is now being incorporated into RNA-specific approaches in the design of RNA inhibitors. Interactions of RNA with proteins, other RNAs, or small molecules often occur through binding mechanisms that follow an induced fit mechanism or a conformational selection mechanism, in which one of several populated RNA conformations is selected through ligand binding. The extent of functional dynamics, including the kinetic formation of a specific RNA tertiary fold, is dependent on the messenger RNA (mRNA) chain length. Thus, during de novo synthesis of mRNA, both in prokaryotes and eukaryotes, nascent mRNA of various lengths will adopt different secondary and tertiary structures. The speed of transcription has a critical influence on the functional dynamics of the RNA being synthesized. In addition to modulating the local dynamics of a conformational RNA ensemble, a given RNA sequence may adopt more than one global, three-dimensional structure. RNA modification is one way to select among these alternative structures, which are often characterized by nearly equal stability, but with high energy barriers for conformational interconversion. The refolding of different secondary and tertiary structures has been found to be a major regulatory mechanism for transcription and translation. These conformational transitions can be characterized with NMR spectroscopy, for any given RNA sequence, in response to external stimuli.
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Affiliation(s)
- Jörg Rinnenthal
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Janina Buck
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Jan Ferner
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Anna Wacker
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Boris FÜrtig
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
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22
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Bothe JR, Nikolova EN, Eichhorn CD, Chugh J, Hansen AL, Al-Hashimi HM. Characterizing RNA dynamics at atomic resolution using solution-state NMR spectroscopy. Nat Methods 2011; 8:919-31. [PMID: 22036746 PMCID: PMC3320163 DOI: 10.1038/nmeth.1735] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Many recently discovered noncoding RNAs do not fold into a single native conformation but sample many different conformations along their free-energy landscape to carry out their biological function. Here we review solution-state NMR techniques that measure the structural, kinetic and thermodynamic characteristics of RNA motions spanning picosecond to second timescales at atomic resolution, allowing unprecedented insights into the RNA dynamic structure landscape. From these studies a basic description of the RNA dynamic structure landscape is emerging, bringing new insights into how RNA structures change to carry out their function as well as applications in RNA-targeted drug discovery and RNA bioengineering.
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Affiliation(s)
- Jameson R. Bothe
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, USA
| | - Evgenia N. Nikolova
- Chemical Biology Doctoral Program, The University of Michigan, Ann Arbor, Michigan, USA
| | - Catherine D. Eichhorn
- Chemical Biology Doctoral Program, The University of Michigan, Ann Arbor, Michigan, USA
| | - Jeetender Chugh
- Department of Biophysics, The University of Michigan, Ann Arbor, Michigan, USA
| | - Alexandar L. Hansen
- Department of Chemistry, The University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, The University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, The University of Toronto, Toronto, Ontario, Canada
| | - Hashim M. Al-Hashimi
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, USA
- Department of Biophysics, The University of Michigan, Ann Arbor, Michigan, USA
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23
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Maldonado AY, Burz DS, Shekhtman A. In-cell NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 59:197-212. [PMID: 21920217 PMCID: PMC3175053 DOI: 10.1016/j.pnmrs.2010.11.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 11/08/2010] [Indexed: 05/23/2023]
Affiliation(s)
- Andres Y Maldonado
- Department of Chemistry, State University of New York at Albany, Albany, NY 12222, USA
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24
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Dominguez C, Schubert M, Duss O, Ravindranathan S, Allain FHT. Structure determination and dynamics of protein-RNA complexes by NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 58:1-61. [PMID: 21241883 DOI: 10.1016/j.pnmrs.2010.10.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 04/24/2010] [Indexed: 05/30/2023]
Affiliation(s)
- Cyril Dominguez
- Institute for Molecular Biology and Biophysics, ETH Zürich, CH-8093 Zürich, Switzerland
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25
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Emani PS, Olsen GL, Echodu DC, Varani G, Drobny GP. Slow exchange model of nonrigid rotational motion in RNA for combined solid-state and solution NMR studies. J Phys Chem B 2010; 114:15991-6002. [PMID: 21067190 PMCID: PMC3246393 DOI: 10.1021/jp107193z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Functional RNA molecules are conformationally dynamic and sample a multitude of dynamic modes over a wide range of frequencies. Thus, a comprehensive description of RNA dynamics requires the inclusion of a broad range of motions across multiple dynamic rates which must be derived from multiple spectroscopies. Here we describe a slow conformational exchange theoretical approach to combining the description of local motions in RNA that occur in the nanosecond to microsecond window and are detected by solid-state NMR with nonrigid rotational motion of the HIV-1 transactivation response element (TAR) RNA in solution as observed by solution NMR. This theoretical model unifies the experimental results generated by solution and solid-state NMR and provides a comprehensive view of the dynamics of HIV-1 TAR RNA, a well-known paradigm of an RNA where function requires extensive conformational rearrangements. This methodology provides a quantitative atomic level view of the amplitudes and rates of the local and collective displacements of the TAR RNA molecule and provides directly motional parameters for the conformational capture hypothesis of this classical RNA-ligand interaction.
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Affiliation(s)
- Prashant S. Emani
- Department of Physics, University of Washington, Box 351560, Seattle, USA 98195
| | - Gregory L. Olsen
- Department of Chemistry, University of Washington, Box 351700, Seattle, USA 98195
| | - Dorothy C. Echodu
- Department of Chemistry, University of Washington, Box 351700, Seattle, USA 98195
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Box 351700, Seattle, USA 98195
- Department of Biochemistry, University of Washington, Box 357350, Seattle, USA 98195
| | - Gary P. Drobny
- Department of Chemistry, University of Washington, Box 351700, Seattle, USA 98195
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26
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Nozinovic S, Richter C, Rinnenthal J, Fürtig B, Duchardt-Ferner E, Weigand JE, Schwalbe H. Quantitative 2D and 3D Gamma-HCP experiments for the determination of the angles alpha and zeta in the phosphodiester backbone of oligonucleotides. J Am Chem Soc 2010; 132:10318-29. [PMID: 20614918 DOI: 10.1021/ja910015n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The quantitative Gamma-(HCP) experiment, a novel heteronuclear NMR pulse sequence for the determination of the RNA backbone angles alpha(O3'(i-1)-P(i)-O5'(i)-C5'(i)) and zeta(C3'(i)-O3'(i)-P(i+1)-O5'(i+1)) in (13)C-labeled RNA, is introduced. The experiment relies on the interaction between the CH bond vector dipole and the (31)P chemical shift anisotropy (CSA), which affects the relaxation of the (13)C,(31)P double- and zero-quantum coherence and thus the intensity of the detectable magnetization. With the new pulse sequence, five different cross-correlated relaxation rates along the phosphodiester backbone can be measured in a quantitative manner, allowing projection-angle and torsion-angle restraints for the two backbone angles alpha and zeta to be extracted. Two versions of the pulse sequence optimized for the CH and CH(2) groups are introduced and demonstrated for a 14-mer cUUCGg tetraloop RNA model system and for a 27-mer RNA with a previously unknown structure. The restraints were incorporated into the calculation of a very high resolution structure of the RNA model system (Nozinovic, S.; et al. Nucleic Acids Res. 2010, 38, 683). Comparison with the X-ray structure of the cUUCGg tetraloop confirmed the high quality of the data, suggesting that the method can significantly improve the quality of RNA structure determination.
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Affiliation(s)
- Senada Nozinovic
- Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
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27
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Riccardi L, Nguyen PH, Stock G. Free-energy landscape of RNA hairpins constructed via dihedral angle principal component analysis. J Phys Chem B 2010; 113:16660-8. [PMID: 20028141 DOI: 10.1021/jp9076036] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To systematically construct a low-dimensional free-energy landscape of RNA systems from a classical molecular dynamics simulation, various versions of the principal component analysis (PCA) are compared: the cPCA using the Cartesian coordinates of all atoms, the dPCA using the sine/cosine-transformed six backbone dihedral angles as well as the glycosidic torsional angle chi and the pseudorotational angle P, the aPCA which ignores the circularity of the 6 + 2 dihedral angles of the RNA, and the dPCA(etatheta), which approximates the 6 backbone dihedral angles by 2 pseudotorsional angles eta and theta. As representative examples, a 10-nucleotide UUCG hairpin and the 36-nucleotide segment SL1 of the Psi site of HIV-1 are studied by classical molecular dynamics simulation, using the Amber all-atom force field and explicit solvent. It is shown that the conformational heterogeneity of the RNA hairpins can only be resolved by an angular PCA such as the dPCA but not by the cPCA using Cartesian coordinates. Apart from possible artifacts due to the coupling of overall and internal motion, this is because the details of hydrogen bonding and stacking interactions but also of global structural rearrangements of the RNA are better discriminated by dihedral angles. In line with recent experiments, it is found that the free energy landscape of RNA hairpins is quite rugged and contains various metastable conformational states which may serve as an intermediate for unfolding.
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Affiliation(s)
- Laura Riccardi
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Str. 7, D-60438 Frankfurt, Germany
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28
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Hänsel R, Foldynová-Trantírková S, Löhr F, Buck J, Bongartz E, Bamberg E, Schwalbe H, Dötsch V, Trantírek L. Evaluation of parameters critical for observing nucleic acids inside living Xenopus laevis oocytes by in-cell NMR spectroscopy. J Am Chem Soc 2010; 131:15761-8. [PMID: 19824671 DOI: 10.1021/ja9052027] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In-cell NMR spectroscopy of proteins in different cellular environments is a well-established technique that, however, has not been applied to nucleic acids so far. Here, we show that isotopically labeled DNA and RNA can be observed inside the eukaryotic environment of Xenopus laevis oocytes by in-cell NMR spectroscopy. One limiting factor for the observation of nucleic acids in Xenopus oocytes is their reduced stability. We demonstrate that chemical modification of DNA and RNA can protect them from degradation and can significantly enhance their lifetime. Finally, we show that the imino region of the NMR spectrum is devoid of any oocyte background signals enabling the detection even of isotopically nonlabeled molecules.
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Affiliation(s)
- Robert Hänsel
- Institute of Biophysical Chemistry, Goethe-University, Max-von-Laue Str. 9, 60438 Frankfurt am Main, Germany
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29
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Ampt KAM, van der Werf RM, Nelissen FHT, Tessari M, Wijmenga SS. The unstable part of the apical stem of duck hepatitis B virus epsilon shows enhanced base pair opening but not pico- to nanosecond dynamics and is essential for reverse transcriptase binding. Biochemistry 2009; 48:10499-508. [PMID: 19817488 DOI: 10.1021/bi9011385] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hepatitis B virus (HBV) replication starts with binding of reverse transcriptase (RT) to the apical stem-loop region of epsilon, a conserved element of the RNA pregenome. For duck HBV, an in vitro replication system has provided molecular details of this interaction. Further insights can be obtained from the structure and dynamics of the duck and human apical stem-loops. Previously, we reported these for the human apical stem-loop. Here, we present the same for the duck counterpart. Unlike its human counterpart, the duck apical stem is unstable in its middle/upper part and contains noncanonical base pairs. This dynamics study is the first of an unstable RNA-DNA stem. Similar to the human stem, the duck apical stem comprises two helical segments with a bend angle of ca. 10 degrees , separated by a nonpaired mobile U residue. It is capped by a well-structured conserved UGUU loop with two residues mobile on the pico- to nanosecond time scale, one of which is involved in RT binding. Remarkably, the unstable middle/upper part of the stem does not show enhanced pico- to nanosecond time scale dynamics. Instead, adenine dispersion relaxation studies indicate enhanced millisecond time scale dynamics involving base pair opening. It can then be concluded that base pair opening is essential for epsilon-RT binding, because stabilization of the stem abolishes binding. We hypothesize that binding occurs by conformational capture of bases in the base pair open state. The unstable secondary structure of the apical stem-loop makes duck epsilon-RT binding unusual in light of recent classifications of RNA target interactions that assume stable secondary structures.
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Affiliation(s)
- Kirsten A M Ampt
- Biophysical Chemistry, Institute of Molecules and Materials, Radboud University of Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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30
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Nozinovic S, Fürtig B, Jonker HRA, Richter C, Schwalbe H. High-resolution NMR structure of an RNA model system: the 14-mer cUUCGg tetraloop hairpin RNA. Nucleic Acids Res 2009; 38:683-94. [PMID: 19906714 PMCID: PMC2811024 DOI: 10.1093/nar/gkp956] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We present a high-resolution nuclear magnetic resonance (NMR) solution structure of a 14-mer RNA hairpin capped by cUUCGg tetraloop. This short and very stable RNA presents an important model system for the study of RNA structure and dynamics using NMR spectroscopy, molecular dynamics (MD) simulations and RNA force-field development. The extraordinary high precision of the structure (root mean square deviation of 0.3 A) could be achieved by measuring and incorporating all currently accessible NMR parameters, including distances derived from nuclear Overhauser effect (NOE) intensities, torsion-angle dependent homonuclear and heteronuclear scalar coupling constants, projection-angle-dependent cross-correlated relaxation rates and residual dipolar couplings. The structure calculations were performed with the program CNS using the ARIA setup and protocols. The structure quality was further improved by a final refinement in explicit water using OPLS force field parameters for non-bonded interactions and charges. In addition, the 2'-hydroxyl groups have been assigned and their conformation has been analyzed based on NOE contacts. The structure currently defines a benchmark for the precision and accuracy amenable to RNA structure determination by NMR spectroscopy. Here, we discuss the impact of various NMR restraints on structure quality and discuss in detail the dynamics of this system as previously determined.
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Affiliation(s)
- Senada Nozinovic
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
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31
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Ferner J, Suhartono M, Breitung S, Jonker HRA, Hennig M, Wöhnert J, Göbel M, Schwalbe H. Structures of HIV TAR RNA-ligand complexes reveal higher binding stoichiometries. Chembiochem 2009; 10:1490-4. [PMID: 19444830 DOI: 10.1002/cbic.200900220] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Target TAR by NMR: Tripeptides containing arginines as terminal residues and non-natural amino acids as central residues are good leads for drug design to target the HIV trans-activation response element (TAR). The structural characterization of the RNA-ligand complex by NMR spectroscopy reveals two specific binding sites that are located at bulge residue U23 and around the pyrimidine-stretch U40-C41-U42 directly adjacent to the bulge.
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Affiliation(s)
- Jan Ferner
- Institut für Organische Chemie und Chemische Biologie, Zentrum für Biomolekulare Magnetische Resonanz (BMRZ), Johann Wolfgang Goethe-Universität Frankfurt am Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
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32
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Rinnenthal J, Richter C, Nozinovic S, Fürtig B, Lopez JJ, Glaubitz C, Schwalbe H. RNA phosphodiester backbone dynamics of a perdeuterated cUUCGg tetraloop RNA from phosphorus-31 NMR relaxation analysis. JOURNAL OF BIOMOLECULAR NMR 2009; 45:143-55. [PMID: 19636800 DOI: 10.1007/s10858-009-9343-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 06/19/2009] [Indexed: 05/13/2023]
Abstract
We have analyzed the relaxation properties of all (31)P nuclei in an RNA cUUCGg tetraloop model hairpin at proton magnetic field strengths of 300, 600 and 900 MHz in solution. Significant H, P dipolar contributions to R (1) and R (2) relaxation are observed in a protonated RNA sample at 600 MHz. These contributions can be suppressed using a perdeuterated RNA sample. In order to interpret the (31)P relaxation data (R (1), R (2)), we measured the (31)P chemical shift anisotropy (CSA) by solid-state NMR spectroscopy under various salt and hydration conditions. A value of 178.5 ppm for the (31)P CSA in the static state (S (2) = 1) could be determined. In order to obtain information about fast time scale dynamics we performed a modelfree analysis on the basis of our relaxation data. The results show that subnanosecond dynamics detected around the phosphodiester backbone are more pronounced than the dynamics detected for the ribofuranosyl and nucleobase moieties of the individual nucleotides (Duchardt and Schwalbe, J Biomol NMR 32:295-308, 2005; Ferner et al., Nucleic Acids Res 36:1928-1940, 2008). Furthermore, the dynamics of the individual phosphate groups seem to be correlated to the 5' neighbouring nucleobases.
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Affiliation(s)
- Jörg Rinnenthal
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, Frankfurt/Main, Germany
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33
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Johnson JE, Hoogstraten CG. Extensive backbone dynamics in the GCAA RNA tetraloop analyzed using 13C NMR spin relaxation and specific isotope labeling. J Am Chem Soc 2009; 130:16757-69. [PMID: 19049467 DOI: 10.1021/ja805759z] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Conformational dynamics play a key role in the properties and functions of proteins and nucleic acids. Heteronuclear NMR spin relaxation is a uniquely powerful site-specific probe of dynamics in proteins and has found increasing applications to nucleotide base side chains and anomeric sites in RNA. Applications to the nucleic acid ribose backbone, however, have been hampered by strong magnetic coupling among ring carbons in uniformly 13C-labeled samples. In this work, we apply a recently developed, metabolically directed isotope labeling scheme that places 13C with high efficiency and specificity at the nucleotide ribose C2' and C4' sites. We take advantage of this scheme to explore backbone dynamics in the well-studied GCAA RNA tetraloop. Using a combination of CPMG (Carr-Purcell-Meiboom-Gill) and R(1rho) relaxation dispersion spectroscopy to explore exchange processes on the microsecond to millisecond time scale, we find an extensive pattern of dynamic transitions connecting a set of relatively well-defined conformations. In many cases, the observed transitions appear to be linked to C3'-endo/C2'-endo sugar pucker transitions of the corresponding nucleotides, and may also be correlated across multiple nucleotides within the tetraloop. These results demonstrate the power of NMR spin relaxation based on alternate-site isotope labeling to open a new window into the dynamic properties of ribose backbone groups in RNA.
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Affiliation(s)
- James E Johnson
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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34
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Brumovská E, Sychrovský V, Vokácová Z, Sponer J, Schneider B, Trantírek L. Effect of local sugar and base geometry on 13C and 15N magnetic shielding anisotropy in DNA nucleosides. JOURNAL OF BIOMOLECULAR NMR 2008; 42:209-223. [PMID: 18853259 DOI: 10.1007/s10858-008-9278-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 09/17/2008] [Accepted: 09/17/2008] [Indexed: 05/26/2023]
Abstract
Density functional theory was employed to study the dependence of 13C and 15N magnetic shielding tensors on the glycosidic torsion angle (chi) and conformation of the sugar ring in 2'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxycytidine, and 2'-deoxythymidine. In general, the magnetic shielding of the glycosidic nitrogens and the sugar carbons was found to depend on both the conformation of the sugar ring and chi. Our calculations indicate that the magnetic shielding anisotropy of the C6 atom in pyrimidine and the C8 atom in purine bases depends strongly on chi. The remaining base carbons were found to be insensitive to both sugar pucker and chi re-orientation. These results call into question the underlying assumptions of currently established methods for interpreting residual chemical shift anisotropies and 13C and 15N auto- and cross-correlated relaxation rates and highlight possible limitations of DNA applications of these methods.
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Affiliation(s)
- Eva Brumovská
- Faculty of Science, University of South Bohemia and Biology Centre AS CR v.v.i., Branisovská 31, 370 05, Ceské Budejovice, Czech Republic
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35
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Gherghe CM, Shajani Z, Wilkinson KA, Varani G, Weeks KM. Strong correlation between SHAPE chemistry and the generalized NMR order parameter (S2) in RNA. J Am Chem Soc 2008; 130:12244-5. [PMID: 18710236 PMCID: PMC2712629 DOI: 10.1021/ja804541s] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The functions of most RNA molecules are critically dependent on the distinct local dynamics that characterize secondary structure and tertiary interactions and on structural changes that occur upon binding by proteins and small molecule ligands. Measurements of RNA dynamics at nucleotide resolution set the foundation for understanding the roles of individual residues in folding, catalysis, and ligand recognition. In favorable cases, local order in small RNAs can be quantitatively analyzed by NMR in terms of a generalized order parameter, S2. Alternatively, SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) chemistry measures local nucleotide flexibility in RNAs of any size using structure-sensitive reagents that acylate the 2'-hydroxyl position. In this work, we compare per-residue RNA dynamics, analyzed by both S2 and SHAPE, for three RNAs: the HIV-1 TAR element, the U1A protein binding site, and the Tetrahymena telomerase stem loop 4. We find a very strong correlation between the two measurements: nucleotides with high SHAPE reactivities consistently have low S2 values. We conclude that SHAPE chemistry quantitatively reports local nucleotide dynamics and can be used with confidence to analyze dynamics in large RNAs, RNA-protein complexes, and RNAs in vivo.
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Affiliation(s)
- Costin M Gherghe
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA
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36
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Oberstrass FC, Allain FHT, Ravindranathan S. Changes in Dynamics of SRE-RNA on Binding to the VTS1p-SAM Domain Studied by 13C NMR Relaxation. J Am Chem Soc 2008; 130:12007-20. [DOI: 10.1021/ja8023115] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Florian C. Oberstrass
- Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zürich, Switzerland, and Central NMR Facility, National Chemical Laboratory, Pune 411008, India
| | - Frédéric H.-T. Allain
- Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zürich, Switzerland, and Central NMR Facility, National Chemical Laboratory, Pune 411008, India
| | - Sapna Ravindranathan
- Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zürich, Switzerland, and Central NMR Facility, National Chemical Laboratory, Pune 411008, India
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37
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Shajani Z, Varani G. 13C relaxation studies of the DNA target sequence for hhai methyltransferase reveal unique motional properties. Biochemistry 2008; 47:7617-25. [PMID: 18578505 DOI: 10.1021/bi7020469] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The goal of this work was to examine if sequence-dependent conformational flexibility in DNA plays a role in base extrusion, a common conformational change induced by many DNA-modifying enzymes. We studied the dynamics of the double-stranded DNA target of the HhaI methyltransferase by recording an extensive set of (13)C NMR relaxation parameters. We observe that the cytidine furanose rings experience fast (picosecond to nanosecond) motions that are not present in other nucleotides; the methylation site experiences particularly high mobility. We also observe that the bases of guanosine and cytidine residues within the HhaI recognition sequence GCGC experience motions on a much slower (1-100 micros) time scale. We compare these observations with previous solution and solid-state NMR studies of the EcoRI nuclease target sequence, and solid-state NMR studies of a similar HhaI target construct. While an increased mobility of cytidine furanose rings compared to those of other nucleotides is observed for both sequences, the slower motions are only observed in the HhaI target DNA. We propose that this inherent flexibility lowers the energetic barriers that must occur when the DNA binds to the HhaI methyltransferase and for extrusion of the cytidine prior to its methylation.
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Affiliation(s)
- Zahra Shajani
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
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38
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Duchardt E, Nilsson L, Schleucher J. Cytosine ribose flexibility in DNA: a combined NMR 13C spin relaxation and molecular dynamics simulation study. Nucleic Acids Res 2008; 36:4211-9. [PMID: 18579564 PMCID: PMC2475628 DOI: 10.1093/nar/gkn375] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Using (13)C spin relaxation NMR in combination with molecular dynamic (MD) simulations, we characterized internal motions within double-stranded DNA on the pico- to nano-second time scale. We found that the C-H vectors in all cytosine ribose moieties within the Dickerson-Drew dodecamer (5'-CGCGAATTCGCG-3') are subject to high amplitude motions, while the other nucleotides are essentially rigid. MD simulations showed that repuckering is a likely motional model for the cytosine ribose moiety. Repuckering occurs with a time constant of around 100 ps. Knowledge of DNA dynamics will contribute to our understanding of the recognition specificity of DNA-binding proteins such as cytosine methyltransferase.
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Affiliation(s)
- Elke Duchardt
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden.
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39
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Olsen GL, Echodu DC, Shajani Z, Bardaro MF, Varani G, Drobny GP. Solid-state deuterium NMR studies reveal micros-ns motions in the HIV-1 transactivation response RNA recognition site. J Am Chem Soc 2008; 130:2896-7. [PMID: 18275190 DOI: 10.1021/ja0778803] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Greg L Olsen
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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40
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Abstract
RNA requires conformational dynamics to undergo its diverse functional roles. Here, a new topological network representation of RNA structures is presented that allows analyzing RNA flexibility/rigidity based on constraint counting. The method extends the FIRST approach, which identifies flexible and rigid regions in atomic detail in a single, static, three-dimensional molecular framework. Initially, the network rigidity of a canonical A-form RNA is analyzed by counting on constraints of network elements of increasing size. These considerations demonstrate that it is the inclusion of hydrophobic contacts into the RNA topological network that is crucial for an accurate flexibility prediction. The counting also explains why a protein-based parameterization results in overly rigid RNA structures. The new network representation is then validated on a tRNA(ASP) structure and all NMR-derived ensembles of RNA structures currently available in the Protein Data Bank (with chain length >/=40). The flexibility predictions demonstrate good agreement with experimental mobility data, and the results are superior compared to predictions based on two previously used network representations. Encouragingly, this holds for flexibility predictions as well as mobility predictions obtained by constrained geometric simulations on these networks. Potential applications of the approach to analyzing the flexibility of DNA and RNA/protein complexes are discussed.
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41
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Ferner J, Villa A, Duchardt E, Widjajakusuma E, Wöhnert J, Stock G, Schwalbe H. NMR and MD studies of the temperature-dependent dynamics of RNA YNMG-tetraloops. Nucleic Acids Res 2008; 36:1928-40. [PMID: 18272534 PMCID: PMC2346598 DOI: 10.1093/nar/gkm1183] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In a combined NMR/MD study, the temperature-dependent changes in the conformation of two members of the RNA YNMG-tetraloop motif (cUUCGg and uCACGg) have been investigated at temperatures of 298, 317 and 325 K. The two members have considerable different thermal stability and biological functions. In order to address these differences, the combined NMR/MD study was performed. The large temperature range represents a challenge for both, NMR relaxation analysis (consistent choice of effective bond length and CSA parameter) and all-atom MD simulation with explicit solvent (necessity to rescale the temperature). A convincing agreement of experiment and theory is found. Employing a principle component analysis of the MD trajectories, the conformational distribution of both hairpins at various temperatures is investigated. The ground state conformation and dynamics of the two tetraloops are indeed found to be very similar. Furthermore, both systems are initially destabilized by a loss of the stacking interactions between the first and the third nucleobase in the loop region. While the global fold is still preserved, this initiation of unfolding is already observed at 317 K for the uCACGg hairpin but at a significantly higher temperature for the cUUCGg hairpin.
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Affiliation(s)
- Jan Ferner
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance, Frankfurt/M, Germany
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42
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Hansen AL, Al-Hashimi HM. Dynamics of large elongated RNA by NMR carbon relaxation. J Am Chem Soc 2007; 129:16072-82. [PMID: 18047338 DOI: 10.1021/ja0757982] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We present an NMR strategy for characterizing picosecond-to-nanosecond internal motions in uniformly 13C/15N-labeled RNAs that combines measurements of R1, R1rho, and heteronuclear 13C{1H} NOEs for protonated base (C2, C5, C6, and C8) and sugar (C1') carbons with a domain elongation strategy for decoupling internal from overall motions and residual dipolar coupling (RDC) measurements for determining the average RNA global conformation and orientation of the principal axis of the axially symmetric rotational diffusion. TROSY-detected pulse sequences are presented for the accurate measurement of nucleobase carbon R1 and R1rho rates in large RNAs. The relaxation data is analyzed using a model free formalism which takes into account the very high anisotropy of overall rotational diffusion (Dratio approximately 4.7), asymmetry of the nucleobase CSAs and noncollinearity of C-C, C-H dipolar and CSA interactions under the assumption that all interaction tensors for a given carbon experience identical isotropic internal motions. The approach is demonstrated and validated on an elongated HIV-1 TAR RNA (taum approximately 18 ns) both in free form and bound to the ligand argininamide (ARG). Results show that, while ARG binding reduces the amplitude of collective helix motions and local mobility at the binding pocket, it leads to a drastic increase in the local mobility of "spacer" bulge residues linking the two helices which undergo virtually unrestricted internal motions (S2 approximately 0.2) in the ARG bound state. Our results establish the ability to quantitatively study the dynamics of RNAs which are significantly larger and more anisotropic than customarily studied by NMR carbon relaxation.
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Affiliation(s)
- Alexandar L Hansen
- Department of Chemistry and Biophysics, The University of Michigan, Ann Arbor, Michigan 48109, USA
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43
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Petzold K, Duchardt E, Flodell S, Larsson G, Kidd-Ljunggren K, Wijmenga S, Schleucher J. Conserved nucleotides in an RNA essential for hepatitis B virus replication show distinct mobility patterns. Nucleic Acids Res 2007; 35:6854-61. [PMID: 17933777 PMCID: PMC2175316 DOI: 10.1093/nar/gkm774] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The number of regulatory RNAs with identified non-canonical structures is increasing, and structural transitions often play a role in their biological function. This stimulates interest in internal motions of RNA, which can underlie structural transitions. Heteronuclear NMR relaxation measurements, which are commonly used to study internal motion, only report on local motions of few sites within the molecule. Here we have studied a 27-nt segment of the human hepatitis B virus (HBV) pregenomic RNA, which is essential for viral replication. We combined heteronuclear relaxation with the new off-resonance ROESY technique, which reports on internal motions of H,H contacts. Using off-resonance ROESY, we could for the first time detect motion of through-space H,H contacts, such as in intra-residue base-ribose contacts or inter-nucleotide contacts, both essential for NMR structure determination. Motions in non-canonical structure elements were found primarily on the sub-nanosecond timescale. Different patterns of mobility were observed among several mobile nucleotides. The most mobile nucleotides are highly conserved among different HBV strains, suggesting that their mobility patterns may be necessary for the RNA’s biological function.
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Affiliation(s)
- Katja Petzold
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
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44
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Farès C, Carlomagno T. SHARP-TACSY: triple-band tailored correlated spectroscopy for base-to-sugar transfer in nucleic acid residues with intermediate time scale motions. J Am Chem Soc 2007; 128:9856-62. [PMID: 16866543 DOI: 10.1021/ja061424h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Established experiments to identify the sugar-to-base connectivity in isotopically labeled RNA require long transfer periods and are inefficient for residues undergoing intermediate time scale motions (microsecond to millisecond). Here, an alternative transfer experiment is introduced, whereby the C1'-N1/9-C6/8 spin system is selectively brought to the so-called Hartmann-Hahn condition using selectiveheteronuclear planar triple-band tailored correlated spectroscopy (SHARP-TACSY). Results are shown for the fully labeled 30-mer oligonucleotide TAR RNA with particular attention placed on residues from and close to the bulge and the loop. For these residues, the faster relaxation can be attributed to exchange contributions stemming from transient stacking and unstacking of the bases and/or from the isomerization of the ribose sugar pucker. The new experiment shows improved signal-to-noise for residues exhibiting large microsecond-millisecond time scale motions with respect to established experiments, thus providing a valid alternative for resonance assignment in mobile RNA regions.
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Affiliation(s)
- Christophe Farès
- Max-Planck-Institute for Biophysical Chemistry, Department of NMR-Based Structural Biology, Am Fassberg 11, D-37077 Göttingen, Germany
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45
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Rinnenthal J, Richter C, Ferner J, Duchardt E, Schwalbe H. Quantitative gamma-HCNCH: determination of the glycosidic torsion angle chi in RNA oligonucleotides from the analysis of CH dipolar cross-correlated relaxation by solution NMR spectroscopy. JOURNAL OF BIOMOLECULAR NMR 2007; 39:17-29. [PMID: 17641824 DOI: 10.1007/s10858-007-9167-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/22/2007] [Accepted: 05/22/2007] [Indexed: 05/16/2023]
Abstract
A novel NMR pulse sequence is introduced to determine the glycosidic torsion angle chi in (13)C,(15)N-labeled oligonucleotides. The quantitative Gamma-HCNCH measures the dipolar cross-correlated relaxation rates Gamma(DD,DD)(C8H8,C1'H1') (pyrimidines) and Gamma(DD,DD)(C6H6,C1'H1') (purines). Cross-correlated relaxation rates of a (13)C,(15)N-labeled RNA 14mer containing a cUUCGg tetraloop were determined and yielded chi-angles that agreed remarkably well with data derived from the X-ray structure of the tetraloop. In addition, the method was applied to the larger stemloop D (SLD) subdomain of the Coxsackievirus B3 cloverleaf 30mer RNA and the effect of anisotropic rotational motion was examined for this molecule. It could be shown that the chi-angle determination especially for nucleotides in the anti conformation was very accurate and the method was ideally suited to distinguish between the syn and the anti-conformation of all four types of nucleotides.
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Affiliation(s)
- Jörg Rinnenthal
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, 60438 Frankfurt/Main, Germany
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46
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Abstract
RNA and DNA molecules experience motions on a wide range of time scales, ranging from rapid localized motions to much slower collective motions of entire helical domains. The many functions of RNA in biology very often require this molecule to change its conformation in response to biological signals in the form of small molecules, proteins or other nucleic acids, whereas local motions in DNA may facilitate protein recognition and allow enzymes acting on DNA to access functional groups on the bases that would otherwise be buried in Watson-Crick base pairs. Although these statements make a compelling case to study the sequence dependent dynamics in nucleic acids, there are few residue-specific studies of nucleic acid dynamics. Fortunately, NMR studies of dynamics of nucleic acids and nucleic acids-protein complexes are gaining increased attention. The aim of this review is to provide an update of the recent progress in studies of nucleic acid dynamics by NMR based on the application of solution relaxation techniques.
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Affiliation(s)
- Zahra Shajani
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
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47
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Shajani Z, Drobny G, Varani G. Binding of U1A protein changes RNA dynamics as observed by 13C NMR relaxation studies. Biochemistry 2007; 46:5875-83. [PMID: 17469848 DOI: 10.1021/bi602658x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Recognition of RNA by proteins and small molecules often involves large changes in RNA structure and dynamics, yet very few studies have so far characterized these motional changes. Here we extend to the protein-bound RNA recent 13C relaxation studies of motions in the RNA recognized by human U1A protein, a well-known model for protein-RNA recognition. Changes in relaxation observed upon complex formation demonstrate that the protein-binding site becomes rigid in the complex, but the upper stem-loop that defines the secondary structure of this RNA experiences unexpected motional freedom. By using a helix elongation strategy, we observe that the upper stem-loop moves independently of the remainder of the structure also in the absence of U1A. Surprisingly, RNA residues making important intermolecular contacts in the structure of the complex exhibit increased flexibility in the presence of the protein. Both of these results support the hypothesis that RNA-binding proteins select a structure that optimizes intermolecular contacts in the manifold of conformations sampled by the free RNA and that protein binding quenches these motions. Together with previous studies of the RNA-bound protein, they also demonstrate that protein-RNA interfaces experience complex motions that modulate the strength of individual interactions.
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Affiliation(s)
- Zahra Shajani
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
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48
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Getz MM, Andrews AJ, Fierke CA, Al-Hashimi HM. Structural plasticity and Mg2+ binding properties of RNase P P4 from combined analysis of NMR residual dipolar couplings and motionally decoupled spin relaxation. RNA (NEW YORK, N.Y.) 2007; 13:251-66. [PMID: 17194721 PMCID: PMC1781369 DOI: 10.1261/rna.264207] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The P4 helix is an essential element of ribonuclease P (RNase P) that is believed to bind catalytically important metals. Here, we applied a combination of NMR residual dipolar couplings (RDCs) and a recently introduced domain-elongation strategy for measuring "motionally decoupled" relaxation data to characterize the structural dynamics of the P4 helix from Bacillus subtilis RNase P. In the absence of divalent ions, the two P4 helical domains undergo small amplitude (approximately 13 degrees) collective motions about an average interhelical angle of 10 degrees. The highly conserved U7 bulge and helical residue C8, which are proposed to be important for substrate recognition and metal binding, are locally mobile at pico- to nanosecond timescales and together form the pivot point for the collective domain motions. Chemical shift mapping reveals significant association of Mg2+ ions at the P4 major groove near the flexible pivot point at residues (A5, G22, G23) previously identified to bind catalytically important metals. The Mg2+ ions do not, however, significantly alter the structure or dynamics of P4. Analysis of results in the context of available X-ray structures of the RNA component of RNase P and structural models that include the pre-tRNA substrate suggest that the internal motions observed in P4 likely facilitate adaptive changes in conformation that take place during folding and substrate recognition, possibly aided by interactions with Mg2+ ions. Our results add to a growing view supporting the existence of functionally important internal motions in RNA occurring at nanosecond timescales.
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Affiliation(s)
- Melissa M Getz
- Department of Chemistry, University of Michigan, Ann Arbor 48109, USA
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49
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Eldho NV, Dayie KT. Internal Bulge and Tetraloop of the Catalytic Domain 5 of a Group II Intron Ribozyme Are Flexible: Implications for Catalysis. J Mol Biol 2007; 365:930-44. [PMID: 17098254 DOI: 10.1016/j.jmb.2006.10.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 09/28/2006] [Accepted: 10/09/2006] [Indexed: 01/27/2023]
Abstract
RNA molecules have an inherent flexibility that enables recognition of other interacting partners through potential disorder-order transitions, yet studies to quantify such motional dynamics remain few. With an increasing database of three-dimensional structures of biologically important RNA molecules, quantifying such motions becomes important to link structural deformations with function. One such system studied intensely is domain 5 (D5) from the self-splicing group II introns, which is at the heart of its catalytic machinery. We report the dynamics of a 36 nucleotide D5 from the Pylaiella littoralis group II intron in the presence and absence of magnesium ions, and at a range of temperatures (298K-318 K). Using high-resolution NMR experiments of heteronuclear nuclear Overhauser enhancement (NOE), spin-lattice (R(1)), and spin-spin (R(2)) (13)C relaxation rates, we determined the rotational diffusion tensor of D5 using the ROTDIF program modified for RNA dynamic analysis (ROTDIF_RNA). The D5 rotational diffusion tensor has an axial symmetric ratio (D(||)/D(perpendicular)) of 1.7+/-0.3, consistent with an estimated overall rotational correlation time of tau(m)=(2D(||)+4D(perpendicular))(-1) of 6.1(+/-0.3) ns at 298 K and 4.1(+/-0.2) ns at 318 K. The measured relaxation data were analyzed with the reduced spectral density mapping formalism using assumed values of the chemical shift anisotropy of the (13)C spins. Both the relaxation data and the values of the spectral density function reveal that the functional groups in D5 implicated in magnesium ion binding and catalysis (catalytic triad, internal bulge, and tetraloop regions) exhibit thermally induced motion on a wide variety of timescales. Because these motions parallel those observed in the intramolecular stem-loop of the U6 element within the spliceosome, we hypothesize that such extensive dynamic disorder likely facilitates D5 engaging both binding and catalytic regions of the ribozyme, and these may be a conserved feature of the catalytic machinery essential for catalysis.
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Affiliation(s)
- Nadukkudy V Eldho
- Department of Molecular Genetics and Center for Structural Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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50
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Musselman C, Pitt SW, Gulati K, Foster LL, Andricioaei I, Al-Hashimi HM. Impact of static and dynamic A-form heterogeneity on the determination of RNA global structural dynamics using NMR residual dipolar couplings. JOURNAL OF BIOMOLECULAR NMR 2006; 36:235-49. [PMID: 17077936 DOI: 10.1007/s10858-006-9087-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 05/12/2023]
Abstract
We examined how static and dynamic deviations from the idealized A-form helix propagate into errors in the principal order tensor parameters determined using residual dipolar couplings (rdcs). A 20-ns molecular dynamics (MD) simulation of the HIV-1 transactivation response element (TAR) RNA together with a survey of spin relaxation studies of RNA dynamics reveals that pico-to-nanosecond local motions in non-terminal Watson-Crick base-pairs will uniformly attenuate base and sugar one bond rdcs by approximately 7%. Gaussian distributions were generated for base and sugar torsion angles through statistical comparison of 40 RNA X-ray structures solved to <3.0 A resolution. For a typical number (>or=11) of one bond C-H base and sugar rdcs, these structural deviations together with rdc uncertainty (1.5 Hz) lead to average errors in the magnitude and orientation of the principal axis of order that are <9% and <4 degrees, respectively. The errors decrease to <5% and <4 degrees for >or=17 rdcs. A protocol that allows for estimation of error in A-form order tensors due to both angular deviations and rdc uncertainty (Aform-RDC) is validated using theoretical simulations and used to analyze rdcs measured previously in TAR in the free state and bound to four distinct ligands. Results confirm earlier findings that the two TAR helices undergo large changes in both their mean relative orientation and dynamics upon binding to different targets.
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Affiliation(s)
- Catherine Musselman
- Department of Chemistry, Biophysics Research Division, & Program in Bioinformatics, The University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109-1055, USA
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