1
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Rao YF, Sun LZ, Luo MB. Na +-Mg 2+ ion effects on conformation and translocation dynamics of single-stranded RNA: Cooperation and competition. Int J Biol Macromol 2024; 267:131273. [PMID: 38569994 DOI: 10.1016/j.ijbiomac.2024.131273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/20/2024] [Accepted: 03/28/2024] [Indexed: 04/05/2024]
Abstract
The nanopore-based translocation of a single-stranded RNA (ssRNA) in mixed salt solution has garnered increasing interest for its biological and technological significance. However, it is challenging to comprehensively understand the effects of the mixed ion species on the translocation dynamics due to their cooperation and competition, which can be directly reflected by the ion screening and neutralizing effects, respectively. In this study, Langevin dynamics simulation is employed to investigate the properties of ssRNA conformation and translocation in mixed Na+-Mg2+ ion environments. Simulation results reveal that the ion screening effect dominates the change in the ssRNA conformational size, the ion neutralizing effect controls the capture rate of the ssRNA by the nanopore, and both of them take charge of the different changes in translocation time of the ssRNA under various mixed ion environments. Under high Na+ ion concentration, as Mg2+ concentration increases, the ion neutralizing effect strengthens, weakening the driving force inside the nanopore, leading to longer translocation time. Conversely, at low Na+ concentration, an increase in Mg2+ concentration enhances the ion screening effect, aiding in faster translocation. Furthermore, these simulation results will be explained by quantitative analysis, advancing a deeper understanding of the complicated effects of the mixed Na+-Mg2+ ions.
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Affiliation(s)
- Yi-Fan Rao
- School of Physics, Zhejiang University, Hangzhou 310027, China; Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China
| | - Li-Zhen Sun
- Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China.
| | - Meng-Bo Luo
- School of Physics, Zhejiang University, Hangzhou 310027, China.
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2
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Zacco E, Broglia L, Kurihara M, Monti M, Gustincich S, Pastore A, Plath K, Nagakawa S, Cerase A, Sanchez de Groot N, Tartaglia GG. RNA: The Unsuspected Conductor in the Orchestra of Macromolecular Crowding. Chem Rev 2024; 124:4734-4777. [PMID: 38579177 PMCID: PMC11046439 DOI: 10.1021/acs.chemrev.3c00575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 04/07/2024]
Abstract
This comprehensive Review delves into the chemical principles governing RNA-mediated crowding events, commonly referred to as granules or biological condensates. We explore the pivotal role played by RNA sequence, structure, and chemical modifications in these processes, uncovering their correlation with crowding phenomena under physiological conditions. Additionally, we investigate instances where crowding deviates from its intended function, leading to pathological consequences. By deepening our understanding of the delicate balance that governs molecular crowding driven by RNA and its implications for cellular homeostasis, we aim to shed light on this intriguing area of research. Our exploration extends to the methodologies employed to decipher the composition and structural intricacies of RNA granules, offering a comprehensive overview of the techniques used to characterize them, including relevant computational approaches. Through two detailed examples highlighting the significance of noncoding RNAs, NEAT1 and XIST, in the formation of phase-separated assemblies and their influence on the cellular landscape, we emphasize their crucial role in cellular organization and function. By elucidating the chemical underpinnings of RNA-mediated molecular crowding, investigating the role of modifications, structures, and composition of RNA granules, and exploring both physiological and aberrant phase separation phenomena, this Review provides a multifaceted understanding of the intriguing world of RNA-mediated biological condensates.
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Affiliation(s)
- Elsa Zacco
- RNA
Systems Biology Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen, 83, 16152 Genova, Italy
| | - Laura Broglia
- RNA
Systems Biology Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen, 83, 16152 Genova, Italy
| | - Misuzu Kurihara
- RNA
Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Michele Monti
- RNA
Systems Biology Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen, 83, 16152 Genova, Italy
| | - Stefano Gustincich
- Central
RNA Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen, 83, 16152 Genova, Italy
| | - Annalisa Pastore
- UK
Dementia Research Institute at the Maurice Wohl Institute of King’s
College London, London SE5 9RT, U.K.
| | - Kathrin Plath
- Department
of Biological Chemistry, David Geffen School
of Medicine at the University of California Los Angeles, Los Angeles, California 90095, United States
| | - Shinichi Nagakawa
- RNA
Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Andrea Cerase
- Blizard
Institute,
Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 4NS, U.K.
- Unit
of Cell and developmental Biology, Department of Biology, Università di Pisa, 56123 Pisa, Italy
| | - Natalia Sanchez de Groot
- Unitat
de Bioquímica, Departament de Bioquímica i Biologia
Molecular, Universitat Autònoma de
Barcelona, 08193 Barcelona, Spain
| | - Gian Gaetano Tartaglia
- RNA
Systems Biology Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen, 83, 16152 Genova, Italy
- Catalan
Institution for Research and Advanced Studies, ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain
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3
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Gong T, Ju F, Bu D. Accurate prediction of RNA secondary structure including pseudoknots through solving minimum-cost flow with learned potentials. Commun Biol 2024; 7:297. [PMID: 38461362 PMCID: PMC10924946 DOI: 10.1038/s42003-024-05952-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/21/2024] [Indexed: 03/11/2024] Open
Abstract
Pseudoknots are key structure motifs of RNA and pseudoknotted RNAs play important roles in a variety of biological processes. Here, we present KnotFold, an accurate approach to the prediction of RNA secondary structure including pseudoknots. The key elements of KnotFold include a learned potential function and a minimum-cost flow algorithm to find the secondary structure with the lowest potential. KnotFold learns the potential from the RNAs with known structures using an attention-based neural network, thus avoiding the inaccuracy of hand-crafted energy functions. The specially designed minimum-cost flow algorithm used by KnotFold considers all possible combinations of base pairs and selects from them the optimal combination. The algorithm breaks the restriction of nested base pairs required by the widely used dynamic programming algorithms, thus enabling the identification of pseudoknots. Using 1,009 pseudoknotted RNAs as representatives, we demonstrate the successful application of KnotFold in predicting RNA secondary structures including pseudoknots with accuracy higher than the state-of-the-art approaches. We anticipate that KnotFold, with its superior accuracy, will greatly facilitate the understanding of RNA structures and functionalities.
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Affiliation(s)
- Tiansu Gong
- Key Lab of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Fusong Ju
- Key Lab of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Dongbo Bu
- Key Lab of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, 100190, Beijing, China.
- University of Chinese Academy of Sciences, 100190, Beijing, China.
- Central China Artificial Intelligence Research Institute, Henan Academy of Sciences, Zhengzhou, 450046, Henan, China.
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4
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Autiero I, Vitagliano L. Enhanced molecular dynamic simulation studies unravel long-range effects caused by sequence variations and partner binding in RNA aptamers. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102039. [PMID: 37869259 PMCID: PMC10585333 DOI: 10.1016/j.omtn.2023.102039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 09/23/2023] [Indexed: 10/24/2023]
Abstract
Intrinsic flexibility and structural modularity are two common features of RNA molecules. Although functionally crucial, RNA plasticity often represents a major complication in high-resolution structural studies. To overcome this problem, RNAs may be rigidified through the complexation with high-affinity partners such as Fab molecules. This approach has been previously used to characterize the DIR2-aptamer. However, possible perturbations induced by the insertion of the Fab binding site on the DIR2-aptamer conformational properties were not investigated. Here, using enhanced molecular dynamics simulations, we compared the dynamics of the DIR2 aptamer holding the Fab binding site with that of the parental sequence. Our results suggest that the L2-loop modification for the Fab recognition leads to a significant increase in local flexibility that also affects the mobility of distant regions. The trajectories provide clear indications of the groups and the interactions mediating the dynamics transfer in DIR2. The effectiveness of our approach in addressing RNA flexibility was further corroborated by showing its ability to reproduce the most important events affecting the NF-κB RNA aptamer upon dissociation from the partner. Therefore, REMD analyses, a rarely adopted technique to unravel the structural/dynamical properties of aptamers, could efficiently complement experimental data guiding the rational design of nucleic acid therapeutics.
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Affiliation(s)
- Ida Autiero
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, Via Pietro Castellino 111, 80131 Naples, Italy
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5
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Luo B, Zhang C, Ling X, Mukherjee S, Jia G, Xie J, Jia X, Liu L, Baulin EF, Luo Y, Jiang L, Dong H, Wei X, Bujnicki JM, Su Z. Cryo-EM reveals dynamics of Tetrahymena group I intron self-splicing. Nat Catal 2023. [DOI: 10.1038/s41929-023-00934-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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6
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Lee WH, Li K, Lu Z. Chemical crosslinking and ligation methods for in vivo analysis of RNA structures and interactions. Methods Enzymol 2023; 691:253-281. [PMID: 37914449 PMCID: PMC10994722 DOI: 10.1016/bs.mie.2023.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
RNA structures and interactions in living cells drive a variety of biological processes and play critical roles in physiology and disease states. However, studies of RNA structures and interactions have been challenging due to limitations in available technologies. Direct determination of structures in vitro has been only possible to a small number of RNAs with limited sizes and conformations. We recently introduced two chemical crosslink-ligation techniques that enabled studies of transcriptome-wide secondary and tertiary structures and their dynamics. In a dramatically improved version of the psoralen analysis of RNA interactions and structures (PARIS2) method, we detailed the synthesis and use of amotosalen, a highly soluble psoralen analogue, and enhanced enzymology for higher efficiency duplex capture. We also introduced spatial 2'-hydroxyl acylation reversible crosslinking (SHARC) with exonuclease (exo) trimming, a method which utilizes a novel crosslinker class that targets the 2'-OH to capture three-dimensional (3D) structures. Both are powerful orthogonal approaches for solving in vivo RNA structure and interactions, integrating crosslinking, exo trimming, proximity ligation, and high throughput sequencing. In this chapter, we present a detailed protocol for the methods and highlight steps that outperform existing crosslink-ligation approaches.
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Affiliation(s)
- Wilson H Lee
- Department of Pharmacology and Pharmaceutical Sciences, Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences
| | - Kongpan Li
- Department of Pharmacology and Pharmaceutical Sciences, Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences
| | - Zhipeng Lu
- Department of Pharmacology and Pharmaceutical Sciences, Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, United States.
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7
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Huang K, Fang X. A review on recent advances in methods for site-directed spin labeling of long RNAs. Int J Biol Macromol 2023; 239:124244. [PMID: 37001783 DOI: 10.1016/j.ijbiomac.2023.124244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/12/2023] [Accepted: 03/15/2023] [Indexed: 03/31/2023]
Abstract
RNAs are important biomolecules that play essential roles in various cellular processes and are crucially linked with many human diseases. The key to elucidate the mechanisms underlying their biological functions and develop RNA-based therapeutics is to investigate RNA structure and dynamics and their connections to function in detail using a variety of approaches. Magnetic resonance techniques including paramagnetic nuclear magnetic resonance (NMR) and electron magnetic resonance (EPR) spectroscopies have proved to be powerful tools to gain insights into such properties. The prerequisites for paramagnetic NMR and EPR studies on RNAs are to achieve site-specific spin labeling of the intrinsically diamagnetic RNAs, which however is not trivial, especially for long ones. In this review, we present some covalent labeling strategies that allow site-specific introduction of electron spins to long RNAs. Generally, these strategies include assembly of long RNAs via enzymatic ligation of short oligonucleotides, co- and post-transcriptional site-specific labeling empowered with the unnatural base pair system, and direct enzymatic functionalization of natural RNAs. We introduce a few case studies to discuss the advantages and limitations of each strategy, and to provide a vision for the future development.
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8
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Zhang H, Zhang L, Liu K, Li S, Mathews DH, Huang L. Linear-Time Algorithms for RNA Structure Prediction. Methods Mol Biol 2023; 2586:15-34. [PMID: 36705896 DOI: 10.1007/978-1-0716-2768-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
RNA secondary structure prediction is widely used to understand RNA function. Existing dynamic programming-based algorithms, both the classical minimum free energy (MFE) methods and partition function methods, suffer from a major limitation: their runtimes scale cubically with the RNA length, and this slowness limits their use in genome-wide applications. Inspired by incremental parsing for context-free grammars in computational linguistics, we designed linear-time heuristic algorithms, LinearFold and LinearPartition, to approximate the MFE structure, partition function and base pairing probabilities. These programs are orders of magnitude faster than Vienna RNAfold and CONTRAfold on long sequences. More interestingly, LinearFold and LinearPartition lead to more accurate predictions on the longest sequence families for which the structures are well established (16S and 23S Ribosomal RNAs), as well as improved accuracies for long-range base pairs (500 + nucleotides apart). This chapter provides protocols for using LinearFold and LinearPartition for secondary structure prediction.
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Affiliation(s)
- He Zhang
- Baidu Research USA, Sunnyvale, CA, USA.,School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - Liang Zhang
- Baidu Research USA, Sunnyvale, CA, USA.,School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - Kaibo Liu
- Baidu Research USA, Sunnyvale, CA, USA
| | - Sizhen Li
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - David H Mathews
- Dept. of Biochemistry & Biophysics, Center for RNA Biology, Rochester, NY, USA.,Dept. of Biostatistics & Computational Biology, University of Rochester Medical Center, Rochester, NY, USA
| | - Liang Huang
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA.
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9
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Ma H, Pham P, Luo B, Rangan R, Kappel K, Su Z, Das R. Auto-DRRAFTER: Automated RNA Modeling Based on Cryo-EM Density. Methods Mol Biol 2023; 2568:193-211. [PMID: 36227570 DOI: 10.1007/978-1-0716-2687-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
RNA three-dimensional structures provide rich and vital information for understanding their functions. Recent advances in cryogenic electron microscopy (cryo-EM) allow structure determination of RNAs and ribonucleoprotein (RNP) complexes. However, limited global and local resolutions of RNA cryo-EM maps pose great challenges in tracing RNA coordinates. The Rosetta-based "auto-DRRAFTER" method builds RNA models into moderate-resolution RNA cryo-EM density as part of the Ribosolve pipeline. Here, we describe a step-by-step protocol for auto-DRRAFTER using a glycine riboswitch from Fusobacterium nucleatum as an example. Successful implementation of this protocol allows automated RNA modeling into RNA cryo-EM density, accelerating our understanding of RNA structure-function relationships. Input and output files are being made available at https://github.com/auto-DRRAFTER/springer-chapter .
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Affiliation(s)
- Haiyun Ma
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Phillip Pham
- Biophysics Program, Stanford University, Stanford, CA, USA
| | - Bingnan Luo
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ramya Rangan
- Biophysics Program, Stanford University, Stanford, CA, USA
| | - Kalli Kappel
- Biophysics Program, Stanford University, Stanford, CA, USA
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Rhiju Das
- Biophysics Program, Stanford University, Stanford, CA, USA.
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10
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Andrałojć W, Wieruszewska J, Pasternak K, Gdaniec Z. Solution Structure of a Lanthanide-binding DNA Aptamer Determined Using High Quality pseudocontact shift restraints. Chemistry 2022; 28:e202202114. [PMID: 36043489 PMCID: PMC9828363 DOI: 10.1002/chem.202202114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Indexed: 01/12/2023]
Abstract
In this contribution we report the high-resolution NMR structure of a recently identified lanthanide-binding aptamer (LnA). We demonstrate that the rigid lanthanide binding by LnA allows for the measurement of anisotropic paramagnetic NMR restraints which to date remain largely inaccessible for nucleic acids. One type of such restraints - pseudocontact shifts (PCS) induced by four different paramagnetic lanthanides - was extensively used throughout the current structure determination study and the measured PCS turned out to be exceptionally well reproduced by the final aptamer structure. This finding opens the perspective for a broader application of paramagnetic effects in NMR studies of nucleic acids through the transplantation of the binding site found in LnA into other DNA/RNA systems.
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Affiliation(s)
- Witold Andrałojć
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Julia Wieruszewska
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Karol Pasternak
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
| | - Zofia Gdaniec
- Institute of Bioorganic ChemistryPolish Academy of SciencesNoskowskiego 12/1461-704 PoznanPoland
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11
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Bonilla SL, Kieft JS. The promise of cryo-EM to explore RNA structural dynamics. J Mol Biol 2022; 434:167802. [PMID: 36049551 PMCID: PMC10084733 DOI: 10.1016/j.jmb.2022.167802] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/24/2022] [Accepted: 08/24/2022] [Indexed: 01/13/2023]
Abstract
Conformational dynamics are essential to macromolecular function. This is certainly true of RNA, whose ability to undergo programmed conformational dynamics is essential to create and regulate complex biological processes. However, methods to easily and simultaneously interrogate both the structure and conformational dynamics of fully functional RNAs in isolation and in complex with proteins have not historically been available. Due to its ability to image and classify single particles, cryogenic electron microscopy (cryo-EM) has the potential to address this gap and may be particularly amenable to exploring structural dynamics within the three-dimensional folds of biologically active RNAs. We discuss the possibilities and current limitations of applying cryo-EM to simultaneously study RNA structure and conformational dynamics, and present one example that illustrates this (as of yet) not fully realized potential.
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Affiliation(s)
- Steve L Bonilla
- Department of Biochemistry and Molecular Genetics, Aurora, CO 80045, USA. https://twitter.com/Steve_Bonilla
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, Aurora, CO 80045, USA; RNA BioScience Initiative, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045, USA.
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12
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Ma H, Jia X, Zhang K, Su Z. Cryo-EM advances in RNA structure determination. Signal Transduct Target Ther 2022; 7:58. [PMID: 35197441 PMCID: PMC8864457 DOI: 10.1038/s41392-022-00916-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/27/2022] [Accepted: 01/30/2022] [Indexed: 02/08/2023] Open
Abstract
Cryo-electron microscopy (cryo-EM) has emerged as an unprecedented tool to resolve protein structures at atomic resolution. Structural insights of biological samples not accessible by conventional X-ray crystallography and NMR can be explored with cryo-EM because measurements are carried out under near-native crystal-free conditions, and large protein complexes with conformational and compositional heterogeneity are readily resolved. RNA has remained underexplored in cryo-EM, despite its essential role in various biological processes. This review highlights current challenges and recent progress in using cryo-EM single-particle analysis to determine protein-free RNA structures, enabled by improvement in sample preparation and integration of multiple structural and biochemical methods.
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Affiliation(s)
- Haiyun Ma
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Xinyu Jia
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Kaiming Zhang
- MOE Key Laboratory for Cellular Dynamics and Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, China
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China.
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13
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Abstract
In recent years, it has become clear that RNA molecules are involved in almost all vital cellular processes and pathogenesis of human disorders. The functional diversity of RNA comes from its structural richness. Although composed of only four nucleotides, RNA molecules present a plethora of secondary and tertiary structures critical for intra and intermolecular contacts with other RNAs and ligands (proteins, small metabolites, etc.). In order to fully understand RNA function it is necessary to define its spatial structure. Crystallography, nuclear magnetic resonance and cryogenic electron microscopy have demonstrated considerable success in determining the structures of biologically important RNA molecules. However, these powerful methods require large amounts of sample. Despite their limitations, chemical synthesis and in vitro transcription are usually employed to obtain milligram quantities of RNA for structural studies, delivering simple and effective methods for large-scale production of homogenous samples. The aim of this paper is to provide an overview of methods for large-scale RNA synthesis with emphasis on chemical synthesis and in vitro transcription. We also present our own results of testing the efficiency of these approaches in order to adapt the material acquisition strategy depending on the desired RNA construct.
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14
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Dagenais P, Desjardins G, Legault P. An integrative NMR-SAXS approach for structural determination of large RNAs defines the substrate-free state of a trans-cleaving Neurospora Varkud Satellite ribozyme. Nucleic Acids Res 2021; 49:11959-11973. [PMID: 34718697 PMCID: PMC8599749 DOI: 10.1093/nar/gkab963] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 09/01/2021] [Accepted: 10/26/2021] [Indexed: 11/26/2022] Open
Abstract
The divide-and-conquer strategy is commonly used for protein structure determination, but its applications to high-resolution structure determination of RNAs have been limited. Here, we introduce an integrative approach based on the divide-and-conquer strategy that was undertaken to determine the solution structure of an RNA model system, the Neurospora VS ribozyme. NMR and SAXS studies were conducted on a minimal trans VS ribozyme as well as several isolated subdomains. A multi-step procedure was used for structure determination that first involved pairing refined NMR structures with SAXS data to obtain structural subensembles of the various subdomains. These subdomain structures were then assembled to build a large set of structural models of the ribozyme, which was subsequently filtered using SAXS data. The resulting NMR-SAXS structural ensemble shares several similarities with the reported crystal structures of the VS ribozyme. However, a local structural difference is observed that affects the global fold by shifting the relative orientation of the two three-way junctions. Thus, this finding highlights a global conformational change associated with substrate binding in the VS ribozyme that is likely critical for its enzymatic activity. Structural studies of other large RNAs should benefit from similar integrative approaches that allow conformational sampling of assembled fragments.
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Affiliation(s)
- Pierre Dagenais
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Box 6128, Downtown Station, Montreal, QC H3C 3J7, Quebec, Canada
| | - Geneviève Desjardins
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Box 6128, Downtown Station, Montreal, QC H3C 3J7, Quebec, Canada
| | - Pascale Legault
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Box 6128, Downtown Station, Montreal, QC H3C 3J7, Quebec, Canada
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15
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Cryo-EM structures of full-length Tetrahymena ribozyme at 3.1 Å resolution. Nature 2021; 596:603-607. [PMID: 34381213 PMCID: PMC8405103 DOI: 10.1038/s41586-021-03803-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/06/2021] [Indexed: 02/07/2023]
Abstract
Single-particle cryogenic electron microscopy (cryo-EM) has become a standard technique for determining protein structures at atomic resolution1-3. However, cryo-EM studies of protein-free RNA are in their early days. The Tetrahymena thermophila group I self-splicing intron was the first ribozyme to be discovered and has been a prominent model system for the study of RNA catalysis and structure-function relationships4, but its full structure remains unknown. Here we report cryo-EM structures of the full-length Tetrahymena ribozyme in substrate-free and bound states at a resolution of 3.1 Å. Newly resolved peripheral regions form two coaxially stacked helices; these are interconnected by two kissing loop pseudoknots that wrap around the catalytic core and include two previously unforeseen (to our knowledge) tertiary interactions. The global architecture is nearly identical in both states; only the internal guide sequence and guanosine binding site undergo a large conformational change and a localized shift, respectively, upon binding of RNA substrates. These results provide a long-sought structural view of a paradigmatic RNA enzyme and signal a new era for the cryo-EM-based study of structure-function relationships in ribozymes.
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16
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Wang Y, Guan X, Zhang S, Liu Y, Wang S, Fan P, Du X, Yan S, Zhang P, Chen HY, Li W, Zhang D, Huang S. Structural-profiling of low molecular weight RNAs by nanopore trapping/translocation using Mycobacterium smegmatis porin A. Nat Commun 2021; 12:3368. [PMID: 34099723 PMCID: PMC8185011 DOI: 10.1038/s41467-021-23764-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022] Open
Abstract
Folding of RNA can produce elaborate tertiary structures, corresponding to their diverse roles in the regulation of biological activities. Direct observation of RNA structures at high resolution in their native form however remains a challenge. The large vestibule and the narrow constriction of a Mycobacterium smegmatis porin A (MspA) suggests a sensing mode called nanopore trapping/translocation, which clearly distinguishes between microRNA, small interfering RNA (siRNA), transfer RNA (tRNA) and 5 S ribosomal RNA (rRNA). To further profit from the acquired event characteristics, a custom machine learning algorithm is developed. Events from measurements with a mixture of RNA analytes can be automatically classified, reporting a general accuracy of ~93.4%. tRNAs, which possess a unique tertiary structure, report a highly distinguishable sensing feature, different from all other RNA types tested in this study. With this strategy, tRNAs from different sources are measured and a high structural conservation across different species is observed in single molecule.
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MESH Headings
- Machine Learning
- MicroRNAs/chemistry
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Molecular Dynamics Simulation
- Molecular Weight
- Mycobacterium smegmatis/genetics
- Mycobacterium smegmatis/metabolism
- Nanopores
- Nucleic Acid Conformation
- Porins/chemistry
- Porins/genetics
- Porins/metabolism
- RNA/chemistry
- RNA/genetics
- RNA/metabolism
- RNA Folding
- RNA Transport
- RNA, Ribosomal, 5S/chemistry
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/metabolism
- RNA, Small Interfering/chemistry
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
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Affiliation(s)
- Yuqin Wang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Xiaoyu Guan
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing, China
| | - Shanyu Zhang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Yao Liu
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Sha Wang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Pingping Fan
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Xiaoyu Du
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Shuanghong Yan
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
| | - Panke Zhang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
| | - Wenfei Li
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing, China
| | - Daoqiang Zhang
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing, China
| | - Shuo Huang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing, China
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17
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Abzhanova A, Hirschi A, Reiter NJ. An exon-biased biophysical approach and NMR spectroscopy define the secondary structure of a conserved helical element within the HOTAIR long non-coding RNA. J Struct Biol 2021; 213:107728. [PMID: 33753203 DOI: 10.1016/j.jsb.2021.107728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/16/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022]
Abstract
HOTAIR is a large, multi-exon spliced non-coding RNA proposed to function as a molecular scaffold and competes with chromatin to bind to histone modification enzymes. Previous sequence analysis and biochemical experiments identified potential conserved regions and characterized the full length HOTAIR secondary structure. Here, we examine the thermodynamic folding properties and structural propensity of the individual exonic regions of HOTAIR using an array of biophysical methods and NMR spectroscopy. We demonstrate that different exons of HOTAIR contain variable degrees of heterogeneity, and identify one exonic region, exon 4, that adopts a stable and compact fold under low magnesium concentrations. Close agreement of NMR spectroscopy and chemical probing unambiguously confirm conserved base pair interactions within the structural element, termed helix 10 of exon 4, located within domain I of human HOTAIR. This combined exon-biased and integrated biophysical approach introduces a new strategy to examine conformational heterogeneity in lncRNAs and emphasizes NMR as a key method to validate base pair interactions and corroborate large RNA secondary structures.
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Affiliation(s)
- Ainur Abzhanova
- Department of Chemistry, Marquette University, Milwaukee 53233, WI, United States
| | - Alexander Hirschi
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville 37205-0146, TN, United States
| | - Nicholas J Reiter
- Department of Chemistry, Marquette University, Milwaukee 53233, WI, United States.
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18
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Zhang H, Zhang L, Mathews DH, Huang L. LinearPartition: linear-time approximation of RNA folding partition function and base-pairing probabilities. Bioinformatics 2021; 36:i258-i267. [PMID: 32657379 PMCID: PMC7355276 DOI: 10.1093/bioinformatics/btaa460] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Motivation RNA secondary structure prediction is widely used to understand RNA function. Recently, there has been a shift away from the classical minimum free energy methods to partition function-based methods that account for folding ensembles and can therefore estimate structure and base pair probabilities. However, the classical partition function algorithm scales cubically with sequence length, and is therefore prohibitively slow for long sequences. This slowness is even more severe than cubic-time free energy minimization due to a substantially larger constant factor in runtime. Results Inspired by the success of our recent LinearFold algorithm that predicts the approximate minimum free energy structure in linear time, we design a similar linear-time heuristic algorithm, LinearPartition, to approximate the partition function and base-pairing probabilities, which is shown to be orders of magnitude faster than Vienna RNAfold and CONTRAfold (e.g. 2.5 days versus 1.3 min on a sequence with length 32 753 nt). More interestingly, the resulting base-pairing probabilities are even better correlated with the ground-truth structures. LinearPartition also leads to a small accuracy improvement when used for downstream structure prediction on families with the longest length sequences (16S and 23S rRNAs), as well as a substantial improvement on long-distance base pairs (500+ nt apart). Availability and implementation Code: http://github.com/LinearFold/LinearPartition; Server: http://linearfold.org/partition. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- He Zhang
- Baidu Research, Sunnyvale, CA 94089, USA.,School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97330, USA
| | - Liang Zhang
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97330, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics, University of Rochester Medical Center, Rochester, NY 48306, USA.,Center for RNA Biology, University of Rochester Medical Center, Rochester, NY 48306, USA.,Department of Biostatistics & Computational Biology, University of Rochester Medical Center, Rochester, NY 48306, USA
| | - Liang Huang
- Baidu Research, Sunnyvale, CA 94089, USA.,School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97330, USA
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19
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Boyd PS, Brown JB, Brown JD, Catazaro J, Chaudry I, Ding P, Dong X, Marchant J, O’Hern CT, Singh K, Swanson C, Summers MF, Yasin S. NMR Studies of Retroviral Genome Packaging. Viruses 2020; 12:v12101115. [PMID: 33008123 PMCID: PMC7599994 DOI: 10.3390/v12101115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/18/2020] [Accepted: 09/26/2020] [Indexed: 12/03/2022] Open
Abstract
Nearly all retroviruses selectively package two copies of their unspliced RNA genomes from a cellular milieu that contains a substantial excess of non-viral and spliced viral RNAs. Over the past four decades, combinations of genetic experiments, phylogenetic analyses, nucleotide accessibility mapping, in silico RNA structure predictions, and biophysical experiments were employed to understand how retroviral genomes are selected for packaging. Genetic studies provided early clues regarding the protein and RNA elements required for packaging, and nucleotide accessibility mapping experiments provided insights into the secondary structures of functionally important elements in the genome. Three-dimensional structural determinants of packaging were primarily derived by nuclear magnetic resonance (NMR) spectroscopy. A key advantage of NMR, relative to other methods for determining biomolecular structure (such as X-ray crystallography), is that it is well suited for studies of conformationally dynamic and heterogeneous systems—a hallmark of the retrovirus packaging machinery. Here, we review advances in understanding of the structures, dynamics, and interactions of the proteins and RNA elements involved in retroviral genome selection and packaging that are facilitated by NMR.
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20
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Xu B, Meng Y, Jin Y. RNA structures in alternative splicing and back-splicing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1626. [PMID: 32929887 DOI: 10.1002/wrna.1626] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 08/14/2020] [Accepted: 08/22/2020] [Indexed: 12/12/2022]
Abstract
Alternative splicing greatly expands the transcriptomic and proteomic diversities related to physiological and developmental processes in higher eukaryotes. Splicing of long noncoding RNAs, and back- and trans- splicing further expanded the regulatory repertoire of alternative splicing. RNA structures were shown to play an important role in regulating alternative splicing and back-splicing. Application of novel sequencing technologies made it possible to identify genome-wide RNA structures and interaction networks, which might provide new insights into RNA splicing regulation in vitro to in vivo. The emerging transcription-folding-splicing paradigm is changing our understanding of RNA alternative splicing regulation. Here, we review the insights into the roles and mechanisms of RNA structures in alternative splicing and back-splicing, as well as how disruption of these structures affects alternative splicing and then leads to human diseases. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Bingbing Xu
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, College of Life Sciences, Zhejiang University, Zhejiang, Hangzhou, China
| | - Yijun Meng
- College of Life and Environmental Sciences, Hangzhou Normal University, Zhejiang, Hangzhou, China
| | - Yongfeng Jin
- MOE Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, College of Life Sciences, Zhejiang University, Zhejiang, Hangzhou, China
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21
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Karlsson H, Baronti L, Petzold K. A robust and versatile method for production and purification of large-scale RNA samples for structural biology. RNA (NEW YORK, N.Y.) 2020; 26:1023-1037. [PMID: 32354720 PMCID: PMC7373988 DOI: 10.1261/rna.075697.120] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 04/25/2020] [Indexed: 05/16/2023]
Abstract
Recent findings in genome-wide transcriptomics revealed that RNAs are involved in almost every biological process, across all domains of life. The characterization of native RNAs of unknown function and structure is particularly challenging due to their typical low abundance in the cell and the inherent sensitivity toward ubiquitous RNA degrading enzymes. Therefore, robust in vitro synthesis and extensive work-up methods are often needed to obtain samples amenable for biochemical, biophysical, and structural studies. Here, we present a protocol that combines the most recent advances in T7 in vitro transcription methodology with reverse phase ion pairing and ion exchange HPLC purification of RNAs for the production of yield-optimized large-scale samples. The method is easy to follow, robust and suitable for users with little or no experience within the field of biochemistry or chromatography. The complete execution of this method, for example, for production of isotopically labeled NMR samples, can be performed in less than a week.
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Affiliation(s)
- Hampus Karlsson
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, SE-104 35 Stockholm, Sweden
| | - Lorenzo Baronti
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, SE-104 35 Stockholm, Sweden
| | - Katja Petzold
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, SE-104 35 Stockholm, Sweden
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22
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Accelerated cryo-EM-guided determination of three-dimensional RNA-only structures. Nat Methods 2020; 17:699-707. [PMID: 32616928 PMCID: PMC7386730 DOI: 10.1038/s41592-020-0878-9] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 05/20/2020] [Indexed: 02/05/2023]
Abstract
The discovery and design of biologically important RNA molecules is outpacing three-dimensional structural characterization. Here, we demonstrate that cryo-electron microscopy can routinely resolve maps of RNA-only systems and that these maps enable subnanometer-resolution coordinate estimation when complemented with multidimensional chemical mapping and Rosetta DRRAFTER computational modeling. This hybrid 'Ribosolve' pipeline detects and falsifies homologies and conformational rearrangements in 11 previously unknown 119- to 338-nucleotide protein-free RNA structures: full-length Tetrahymena ribozyme, hc16 ligase with and without substrate, full-length Vibrio cholerae and Fusobacterium nucleatum glycine riboswitch aptamers with and without glycine, Mycobacterium SAM-IV riboswitch with and without S-adenosylmethionine, and the computer-designed ATP-TTR-3 aptamer with and without AMP. Simulation benchmarks, blind challenges, compensatory mutagenesis, cross-RNA homologies and internal controls demonstrate that Ribosolve can accurately resolve the global architectures of RNA molecules but does not resolve atomic details. These tests offer guidelines for making inferences in future RNA structural studies with similarly accelerated throughput.
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23
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Zhang H, Keane SC. Advances that facilitate the study of large RNA structure and dynamics by nuclear magnetic resonance spectroscopy. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1541. [PMID: 31025514 PMCID: PMC7169810 DOI: 10.1002/wrna.1541] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/18/2019] [Accepted: 04/02/2019] [Indexed: 12/22/2022]
Abstract
The characterization of functional yet nonprotein coding (nc) RNAs has expanded the role of RNA in the cell from a passive player in the central dogma of molecular biology to an active regulator of gene expression. The misregulation of ncRNA function has been linked with a variety of diseases and disorders ranging from cancers to neurodegeneration. However, a detailed molecular understanding of how ncRNAs function has been limited; due, in part, to the difficulties associated with obtaining high-resolution structures of large RNAs. Tertiary structure determination of RNA as a whole is hampered by various technical challenges, all of which are exacerbated as the size of the RNA increases. Namely, RNAs tend to be highly flexible and dynamic molecules, which are difficult to crystallize. Biomolecular nuclear magnetic resonance (NMR) spectroscopy offers a viable alternative to determining the structure of large RNA molecules that do not readily crystallize, but is itself hindered by some technical limitations. Recently, a series of advancements have allowed the biomolecular NMR field to overcome, at least in part, some of these limitations. These advances include improvements in sample preparation strategies as well as methodological improvements. Together, these innovations pave the way for the study of ever larger RNA molecules that have important biological function. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Huaqun Zhang
- Biophysics Program, University of Michigan, Ann Arbor, Michigan
| | - Sarah C Keane
- Biophysics Program, University of Michigan, Ann Arbor, Michigan.,Department of Chemistry, University of Michigan, Ann Arbor, Michigan
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