1
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Zhou L, Wang X, Yu S, Tan YL, Tan ZJ. FebRNA: An automated fragment-ensemble-based model for building RNA 3D structures. Biophys J 2022; 121:3381-3392. [PMID: 35978551 PMCID: PMC9515226 DOI: 10.1016/j.bpj.2022.08.017] [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: 04/30/2022] [Revised: 07/19/2022] [Accepted: 08/15/2022] [Indexed: 11/23/2022] Open
Abstract
Knowledge of RNA three-dimensional (3D) structures is critical to understanding the important biological functions of RNAs. Although various structure prediction models have been developed, the high-accuracy predictions of RNA 3D structures are still limited to the RNAs with short lengths or with simple topology. In this work, we proposed a new model, namely FebRNA, for building RNA 3D structures through fragment assembly based on coarse-grained (CG) fragment ensembles. Specifically, FebRNA is composed of four processes: establishing the library of different types of non-redundant CG fragment ensembles regardless of the sequences, building CG 3D structure ensemble through fragment assembly, identifying top-scored CG structures through a specific CG scoring function, and rebuilding the all-atom structures from the top-scored CG ones. Extensive examination against different types of RNA structures indicates that FebRNA consistently gives the reliable predictions on RNA 3D structures, including pseudoknots, three-way junctions, four-way and five-way junctions, and RNAs in the RNA-Puzzles. FebRNA is available on the Web site: https://github.com/Tan-group/FebRNA.
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Affiliation(s)
- Li Zhou
- Department of Physics and Key Laboratory of Artificial Micro & Nano-structures of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Xunxun Wang
- Department of Physics and Key Laboratory of Artificial Micro & Nano-structures of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Shixiong Yu
- Department of Physics and Key Laboratory of Artificial Micro & Nano-structures of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Ya-Lan Tan
- Research Center of Nonlinear Science, School of Mathematical and Physical Sciences, Wuhan Textile University, Wuhan 430073, China.
| | - Zhi-Jie Tan
- Department of Physics and Key Laboratory of Artificial Micro & Nano-structures of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
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2
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Grytsyk N, Cianfarani D, Crégut O, Richert L, Boudier C, Humbert N, Didier P, Mély Y, Léonard J. Kinetics of protein-assisted nucleic acid interconversion monitored by transient time resolved fluorescence in microfluidic droplets. Nucleic Acids Res 2021; 49:e111. [PMID: 34450653 PMCID: PMC8565319 DOI: 10.1093/nar/gkab687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/29/2021] [Accepted: 08/24/2021] [Indexed: 11/25/2022] Open
Abstract
Interconversions between nucleic acid structures play an important role in transcriptional and translational regulation and also in repair and recombination. These interconversions are frequently promoted by nucleic acid chaperone proteins. To monitor their kinetics, Förster resonance energy transfer (FRET) is widely exploited using ensemble fluorescence intensity measurements in pre-steady-state stopped-flow experiments. Such experiments only provide a weighted average of the emission of all species in solution and consume large quantities of materials. Herein, we lift these limitations by combining time-resolved fluorescence (TRF) with droplet microfluidics (DmF). We validate the innovative TRF-DmF approach by investigating the well characterized annealing of the HIV-1 (+)/(–) Primer Binding Sequences (PBS) promoted by a HIV-1 nucleocapsid peptide. Upon rapid mixing of the FRET-labelled (–)PBS with its complementary (+)PBS sequence inside microdroplets, the TRF-DmF set-up enables resolving the time evolution of sub-populations of reacting species and reveals an early intermediate with a ∼50 ps donor fluorescence lifetime never identified so far. TRF-DmF also favorably compares with single molecule experiments, as it offers an accurate control of concentrations with no upper limit, no need to graft one partner on a surface and no photobleaching issues.
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Affiliation(s)
- Natalia Grytsyk
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg & CNRS, 67034 Strasbourg, France.,Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Damien Cianfarani
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg & CNRS, 67034 Strasbourg, France
| | - Olivier Crégut
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg & CNRS, 67034 Strasbourg, France
| | - Ludovic Richert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Christian Boudier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Nicolas Humbert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Jérémie Léonard
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg & CNRS, 67034 Strasbourg, France
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3
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Fairman CW, Lever AML, Kenyon JC. Evaluating RNA Structural Flexibility: Viruses Lead the Way. Viruses 2021; 13:v13112130. [PMID: 34834937 PMCID: PMC8624864 DOI: 10.3390/v13112130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/12/2021] [Accepted: 10/18/2021] [Indexed: 12/11/2022] Open
Abstract
Our understanding of RNA structure has lagged behind that of proteins and most other biological polymers, largely because of its ability to adopt multiple, and often very different, functional conformations within a single molecule. Flexibility and multifunctionality appear to be its hallmarks. Conventional biochemical and biophysical techniques all have limitations in solving RNA structure and to address this in recent years we have seen the emergence of a wide diversity of techniques applied to RNA structural analysis and an accompanying appreciation of its ubiquity and versatility. Viral RNA is a particularly productive area to study in that this economy of function within a single molecule admirably suits the minimalist lifestyle of viruses. Here, we review the major techniques that are being used to elucidate RNA conformational flexibility and exemplify how the structure and function are, as in all biology, tightly linked.
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Affiliation(s)
| | - Andrew M. L. Lever
- Department of Medicine, Cambridge University, Level 5, Addenbrookes’ Hospital (Box 157), Cambridge CB2 0QQ, UK
- Correspondence: (A.M.L.L.); (J.C.K.); Tel.: +44-(0)-1223-747308 (A.M.L.L. & J.C.K.)
| | - Julia C. Kenyon
- Homerton College, University of Cambridge, Cambridge CB2 8PH, UK;
- Department of Medicine, Cambridge University, Level 5, Addenbrookes’ Hospital (Box 157), Cambridge CB2 0QQ, UK
- Correspondence: (A.M.L.L.); (J.C.K.); Tel.: +44-(0)-1223-747308 (A.M.L.L. & J.C.K.)
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4
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Pujari N, Saundh SL, Acquah FA, Mooers BHM, Ferré-D’Amaré AR, Leung AKW. Engineering Crystal Packing in RNA Structures I: Past and Future Strategies for Engineering RNA Packing in Crystals. CRYSTALS 2021; 11:952. [PMID: 34745656 PMCID: PMC8570644 DOI: 10.3390/cryst11080952] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
X-ray crystallography remains a powerful method to gain atomistic insights into the catalytic and regulatory functions of RNA molecules. However, the technique requires the preparation of diffraction-quality crystals. This is often a resource- and time-consuming venture because RNA crystallization is hindered by the conformational heterogeneity of RNA, as well as the limited opportunities for stereospecific intermolecular interactions between RNA molecules. The limited success at crystallization explains in part the smaller number of RNA-only structures in the Protein Data Bank. Several approaches have been developed to aid the formation of well-ordered RNA crystals. The majority of these are construct-engineering techniques that aim to introduce crystal contacts to favor the formation of well-diffracting crystals. A typical example is the insertion of tetraloop-tetraloop receptor pairs into non-essential RNA segments to promote intermolecular association. Other methods of promoting crystallization involve chaperones and crystallization-friendly molecules that increase RNA stability and improve crystal packing. In this review, we discuss the various techniques that have been successfully used to facilitate crystal packing of RNA molecules, recent advances in construct engineering, and directions for future research in this vital aspect of RNA crystallography.
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Affiliation(s)
- Narsimha Pujari
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Stephanie L. Saundh
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Francis A. Acquah
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Blaine H. M. Mooers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Adrian R. Ferré-D’Amaré
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Adelaine Kwun-Wai Leung
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
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5
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Structural Insights into RNA Dimerization: Motifs, Interfaces and Functions. Molecules 2020; 25:molecules25122881. [PMID: 32585844 PMCID: PMC7357161 DOI: 10.3390/molecules25122881] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 12/26/2022] Open
Abstract
In comparison with the pervasive use of protein dimers and multimers in all domains of life, functional RNA oligomers have so far rarely been observed in nature. Their diminished occurrence contrasts starkly with the robust intrinsic potential of RNA to multimerize through long-range base-pairing ("kissing") interactions, self-annealing of palindromic or complementary sequences, and stable tertiary contact motifs, such as the GNRA tetraloop-receptors. To explore the general mechanics of RNA dimerization, we performed a meta-analysis of a collection of exemplary RNA homodimer structures consisting of viral genomic elements, ribozymes, riboswitches, etc., encompassing both functional and fortuitous dimers. Globally, we found that domain-swapped dimers and antiparallel, head-to-tail arrangements are predominant architectural themes. Locally, we observed that the same structural motifs, interfaces and forces that enable tertiary RNA folding also drive their higher-order assemblies. These feature prominently long-range kissing loops, pseudoknots, reciprocal base intercalations and A-minor interactions. We postulate that the scarcity of functional RNA multimers and limited diversity in multimerization motifs may reflect evolutionary constraints imposed by host antiviral immune surveillance and stress sensing. A deepening mechanistic understanding of RNA multimerization is expected to facilitate investigations into RNA and RNP assemblies, condensates, and granules and enable their potential therapeutical targeting.
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6
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Fang Y, Tu J, Han D, Guo Y, Hong W, Wei W. The effects of long non-coding ribonucleic acids on various cellular components in rheumatoid arthritis. Rheumatology (Oxford) 2020; 59:46-56. [PMID: 31605483 PMCID: PMC6909907 DOI: 10.1093/rheumatology/kez472] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/07/2019] [Indexed: 01/13/2023] Open
Abstract
RA is a chronic, autoimmune-mediated inflammatory pathology. Long non-coding RNAs (lncRNAs) are a novel group of non-coding RNAs with a length of >200 nucleotides. There are reports emerging that suggest that lncRNAs participate in establishing and sustaining autoimmune diseases, including RA. In this review article, we highlight the functions of lncRNAs in different cell types in RA. Our review indicates that lncRNAs affect various cellular components and are novel candidates that could constitute promising targets for the diagnosis and treatment of RA.
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Affiliation(s)
- Yilong Fang
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
| | - Jiajie Tu
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
| | - Dafei Han
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
| | - Yawei Guo
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
| | - Wenming Hong
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
| | - Wei Wei
- Institute of Clinical Pharmacology, Hefei, China.,Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
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7
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Frezza E, Courban A, Allouche D, Sargueil B, Pasquali S. The interplay between molecular flexibility and RNA chemical probing reactivities analyzed at the nucleotide level via an extensive molecular dynamics study. Methods 2019; 162-163:108-127. [PMID: 31145972 DOI: 10.1016/j.ymeth.2019.05.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 05/22/2019] [Accepted: 05/22/2019] [Indexed: 12/20/2022] Open
Abstract
Determination of the tridimensional structure of ribonucleic acid molecules is fundamental for understanding their function in the cell. A common method to investigate RNA structures of large molecules is the use of chemical probes such as SHAPE (2'-hydroxyl acylation analyzed by primer extension) reagents, DMS (dimethyl sulfate) and CMCT (1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfate), the reaction of which is dependent on the local structural properties of each nucleotide. In order to understand the interplay between local flexibility, sugar pucker, canonical pairing and chemical reactivity of the probes, we performed all-atom molecular dynamics simulations on a set of RNA molecules for which both tridimensional structure and chemical probing data are available and we analyzed the correlations between geometrical parameters and the chemical reactivity. Our study confirms that SHAPE reactivity is guided by the local flexibility of the different chemical moieties but suggests that a combination of multiple parameters is needed to better understand the implications of the reactivity at the molecular level. This is also the case for DMS and CMCT for which the reactivity appears to be more complex than commonly accepted.
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Affiliation(s)
- Elisa Frezza
- Faculté de Pharmacie de Paris, Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 - CNRS, Université Paris Descartes, 4 Avenue de l'Observatoire 75270 PARIS CEDEX 06, France.
| | - Antoine Courban
- Faculté de Pharmacie de Paris, Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 - CNRS, Université Paris Descartes, 4 Avenue de l'Observatoire 75270 PARIS CEDEX 06, France
| | - Delphine Allouche
- Faculté de Pharmacie de Paris, Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 - CNRS, Université Paris Descartes, 4 Avenue de l'Observatoire 75270 PARIS CEDEX 06, France
| | - Bruno Sargueil
- Faculté de Pharmacie de Paris, Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 - CNRS, Université Paris Descartes, 4 Avenue de l'Observatoire 75270 PARIS CEDEX 06, France.
| | - Samuela Pasquali
- Faculté de Pharmacie de Paris, Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 - CNRS, Université Paris Descartes, 4 Avenue de l'Observatoire 75270 PARIS CEDEX 06, France.
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8
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Lieberman J. Tapping the RNA world for therapeutics. Nat Struct Mol Biol 2018; 25:357-364. [PMID: 29662218 DOI: 10.1038/s41594-018-0054-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 03/13/2018] [Indexed: 01/08/2023]
Abstract
A recent revolution in RNA biology has led to the identification of new RNA classes with unanticipated functions, new types of RNA modifications, an unexpected multiplicity of alternative transcripts and widespread transcription of extragenic regions. This development in basic RNA biology has spawned a corresponding revolution in RNA-based strategies to generate new types of therapeutics. Here, I review RNA-based drug design and discuss barriers to broader applications and possible ways to overcome them. Because they target nucleic acids rather than proteins, RNA-based drugs promise to greatly extend the domain of 'druggable' targets beyond what can be achieved with small molecules and biologics.
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Affiliation(s)
- Judy Lieberman
- Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
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9
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Zhang D, Chen SJ. IsRNA: An Iterative Simulated Reference State Approach to Modeling Correlated Interactions in RNA Folding. J Chem Theory Comput 2018; 14:2230-2239. [PMID: 29499114 DOI: 10.1021/acs.jctc.7b01228] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Coarse-grained RNA folding models promise great potential for RNA structure prediction. A key component in a coarse-grained folding model is the force field. One of the challenges in the coarse-grained force field calculation is how to treat the correlation between the different degrees of freedoms. Here, we describe a new approach (IsRNA) to extract the correlated energy functions from the known structures. Through iterative molecular dynamics simulations, we build the correlation effects into the reference states, from which we extract the energy functions. The validity of IsRNA is supported by the close agreement between the simulated Boltzmann-like probability distributions for all the structure parameters and those observed from the experimentally determined structures. The correlated energy functions derived here may provide a new tool for RNA 3D structure prediction.
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Affiliation(s)
- Dong Zhang
- Department of Physics, Department of Biochemistry, and MU Informatics Institute , University of Missouri , Columbia , Missouri 65211 , United States
| | - Shi-Jie Chen
- Department of Physics, Department of Biochemistry, and MU Informatics Institute , University of Missouri , Columbia , Missouri 65211 , United States
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10
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Dršata T, Réblová K, Beššeová I, Šponer J, Lankaš F. rRNA C-Loops: Mechanical Properties of a Recurrent Structural Motif. J Chem Theory Comput 2017; 13:3359-3371. [DOI: 10.1021/acs.jctc.7b00061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tomáš Dršata
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
| | - Kamila Réblová
- CEITEC—Central European Institute of Technology, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Ivana Beššeová
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
| | - Jiří Šponer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Královopolská
135, 612 65 Brno, Czech Republic
- CEITEC—Central European Institute of Technology, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Filip Lankaš
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
- Laboratory
of Informatics and Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech Republic
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11
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Blouin S, Craggs TD, Lafontaine DA, Penedo JC. Functional Studies of DNA-Protein Interactions Using FRET Techniques. Methods Mol Biol 2016; 1334:115-41. [PMID: 26404147 DOI: 10.1007/978-1-4939-2877-4_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Protein-DNA interactions underpin life and play key roles in all cellular processes and functions including DNA transcription, packaging, replication, and repair. Identifying and examining the nature of these interactions is therefore a crucial prerequisite to understand the molecular basis of how these fundamental processes take place. The application of fluorescence techniques and in particular fluorescence resonance energy transfer (FRET) to provide structural and kinetic information has experienced a stunning growth during the past decade. This has been mostly promoted by new advances in the preparation of dye-labeled nucleic acids and proteins and in optical sensitivity, where its implementation at the level of individual molecules has opened a new biophysical frontier. Nowadays, the application of FRET-based techniques to the analysis of protein-DNA interactions spans from the classical steady-state and time-resolved methods averaging over large ensembles to the analysis of distances, conformational changes, and enzymatic reactions in individual protein-DNA complexes. This chapter introduces the practical aspects of applying these methods for the study of protein-DNA interactions.
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Affiliation(s)
- Simon Blouin
- Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | | | - Daniel A Lafontaine
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, 2500 Boulevard de L'Université, Sherbrooke, QC, Canada, J1K 2R1.
| | - J Carlos Penedo
- School of Physics and Astronomy, University of St. Andrews, St. Andrews, UK
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12
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Gelinas AD, Davies DR, Janjic N. Embracing proteins: structural themes in aptamer-protein complexes. Curr Opin Struct Biol 2016; 36:122-32. [PMID: 26919170 DOI: 10.1016/j.sbi.2016.01.009] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/13/2016] [Accepted: 01/15/2016] [Indexed: 01/17/2023]
Abstract
Understanding the structural rules that govern specific, high-affinity binding characteristic of aptamer-protein interactions is important in view of the increasing use of aptamers across many applications. From the modest number of 16 aptamer-protein structures currently available, trends are emerging. The flexible phosphodiester backbone allows folding into precise three-dimensional structures using known nucleic acid motifs as scaffolds that orient specific functional groups for target recognition. Still, completely novel motifs essential for structure and function are found in modified aptamers with diversity-enhancing side chains. Aptamers and antibodies, two classes of macromolecules used as affinity reagents with entirely different backbones and composition, recognize protein epitopes of similar size and with comparably high shape complementarity.
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Affiliation(s)
- Amy D Gelinas
- SomaLogic, Inc., 2945 Wilderness Place, Boulder, CO 80301, United States
| | - Douglas R Davies
- Beryllium, 7869 NE Day Road West, Bainbridge Island, WA 98110, United States
| | - Nebojsa Janjic
- SomaLogic, Inc., 2945 Wilderness Place, Boulder, CO 80301, United States.
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13
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Réblová M, Jaklitsch WM, Réblová K, Štěpánek V. Phylogenetic Reconstruction of the Calosphaeriales and Togniniales Using Five Genes and Predicted RNA Secondary Structures of ITS, and Flabellascus tenuirostris gen. et sp. nov. PLoS One 2015; 10:e0144616. [PMID: 26699541 PMCID: PMC4689446 DOI: 10.1371/journal.pone.0144616] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/20/2015] [Indexed: 11/18/2022] Open
Abstract
The Calosphaeriales is revisited with new collection data, living cultures, morphological studies of ascoma centrum, secondary structures of the internal transcribed spacer (ITS) rDNA and phylogeny based on novel DNA sequences of five nuclear ribosomal and protein-coding loci. Morphological features, molecular evidence and information from predicted RNA secondary structures of ITS converged upon robust phylogenies of the Calosphaeriales and Togniniales. The current concept of the Calosphaeriales includes the Calosphaeriaceae and Pleurostomataceae encompassing five monophyletic genera, Calosphaeria, Flabellascus gen. nov., Jattaea, Pleurostoma and Togniniella, strongly supported by Bayesian and Maximum Likelihood methods. The structural elements of ITS1 form characteristic patterns that are phylogenetically conserved, corroborate observations based on morphology and have a high predictive value at the generic level. Three major clades containing 44 species of Phaeoacremonium were recovered in the closely related Togniniales based on ITS, actin and β-tubulin sequences. They are newly characterized by sexual and RNA structural characters and ecology. This approach is a first step towards understanding of the molecular systematics of Phaeoacremonium and possibly its new classification. In the Calosphaeriales, Jattaea aphanospora sp. nov. and J. ribicola sp. nov. are introduced, Calosphaeria taediosa is combined in Jattaea and epitypified. The sexual morph of Phaeoacremonium cinereum was encountered for the first time on decaying wood and obtained in vitro. In order to achieve a single nomenclature, the genera of asexual morphs linked with the Calosphaeriales are transferred to synonymy of their sexual morphs following the principle of priority, i.e. Calosphaeriophora to Calosphaeria, Phaeocrella to Togniniella and Pleurostomophora to Pleurostoma. Three new combinations are proposed, i.e. Pleurostoma ochraceum comb. nov., P. repens comb. nov. and P. richardsiae comb. nov. The morphology-based key is provided to facilitate identification of genera accepted in the Calosphaeriales.
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Affiliation(s)
- Martina Réblová
- Department of Taxonomy, Institute of Botany of the Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
- * E-mail:
| | - Walter M. Jaklitsch
- Department of Forest and Soil Sciences, Forest Pathology and Forest Protection, Institute of Forest Entomology, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
- Department of Botany and Biodiversity Research, Division of Systematic and Evolutionary Botany, University of Vienna, Vienna, Austria
| | - Kamila Réblová
- Faculty of Medicine, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Václav Štěpánek
- Laboratory of Enzyme Technology, Institute of Microbiology of the Academy of Sciences of the Czech Republic, Prague, Czech Republic
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14
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Dwell-Time Distribution, Long Pausing and Arrest of Single-Ribosome Translation through the mRNA Duplex. Int J Mol Sci 2015; 16:23723-44. [PMID: 26473825 PMCID: PMC4632723 DOI: 10.3390/ijms161023723] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 09/18/2015] [Accepted: 09/23/2015] [Indexed: 12/31/2022] Open
Abstract
Proteins in the cell are synthesized by a ribosome translating the genetic information encoded on the single-stranded messenger RNA (mRNA). It has been shown that the ribosome can also translate through the duplex region of the mRNA by unwinding the duplex. Here, based on our proposed model of the ribosome translation through the mRNA duplex we study theoretically the distribution of dwell times of the ribosome translation through the mRNA duplex under the effect of a pulling force externally applied to the ends of the mRNA to unzip the duplex. We provide quantitative explanations of the available single molecule experimental data on the distribution of dwell times with both short and long durations, on rescuing of the long paused ribosomes by raising the pulling force to unzip the duplex, on translational arrests induced by the mRNA duplex and Shine-Dalgarno(SD)-like sequence in the mRNA. The functional consequences of the pauses or arrests caused by the mRNA duplex and the SD sequence are discussed and compared with those obtained from other types of pausing, such as those induced by "hungry" codons or interactions of specific sequences in the nascent chain with the ribosomal exit tunnel.
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15
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Drory Retwitzer M, Kifer I, Sengupta S, Yakhini Z, Barash D. An Efficient Minimum Free Energy Structure-Based Search Method for Riboswitch Identification Based on Inverse RNA Folding. PLoS One 2015; 10:e0134262. [PMID: 26230932 PMCID: PMC4521916 DOI: 10.1371/journal.pone.0134262] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 07/07/2015] [Indexed: 11/22/2022] Open
Abstract
Riboswitches are RNA genetic control elements that were originally discovered in bacteria and provide a unique mechanism of gene regulation. They work without the participation of proteins and are believed to represent ancient regulatory systems in the evolutionary timescale. One of the biggest challenges in riboswitch research is to find additional eukaryotic riboswitches since more than 20 riboswitch classes have been found in prokaryotes but only one class has been found in eukaryotes. Moreover, this single known class of eukaryotic riboswitch, namely the TPP riboswitch class, has been found in bacteria, archaea, fungi and plants but not in animals. The few examples of eukaryotic riboswitches were identified using sequence-based bioinformatics search methods such as a combination of BLAST and pattern matching techniques that incorporate base-pairing considerations. None of these approaches perform energy minimization structure predictions. There is a clear motivation to develop new bioinformatics methods, aside of the ongoing advances in covariance models, that will sample the sequence search space more flexibly using structural guidance while retaining the computational efficiency of sequence-based methods. We present a new energy minimization approach that transforms structure-based search into a sequence-based search, thereby enabling the utilization of well established sequence-based search utilities such as BLAST and FASTA. The transformation to sequence space is obtained by using an extended inverse RNA folding problem solver with sequence and structure constraints, available within RNAfbinv. Examples in applying the new method are presented for the purine and preQ1 riboswitches. The method is described in detail along with its findings in prokaryotes. Potential uses in finding novel eukaryotic riboswitches and optimizing pre-designed synthetic riboswitches based on ligand simulations are discussed. The method components are freely available for use.
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Affiliation(s)
| | - Ilona Kifer
- Agilent Laboratories, Tel Aviv, Israel; Microsoft R&D Center, Herzliya, Israel
| | - Supratim Sengupta
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Zohar Yakhini
- Agilent Laboratories, Tel Aviv, Israel; Laboratory of Computational Biology, Computer Science Department, Israel Institute of Technology, Haifa, 32000, Israel
| | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva, 84105, Israel
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16
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Cragnolini T, Derreumaux P, Pasquali S. Ab initio RNA folding. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:233102. [PMID: 25993396 DOI: 10.1088/0953-8984/27/23/233102] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
RNA molecules are essential cellular machines performing a wide variety of functions for which a specific three-dimensional structure is required. Over the last several years, the experimental determination of RNA structures through x-ray crystallography and NMR seems to have reached a plateau in the number of structures resolved each year, but as more and more RNA sequences are being discovered, the need for structure prediction tools to complement experimental data is strong. Theoretical approaches to RNA folding have been developed since the late nineties, when the first algorithms for secondary structure prediction appeared. Over the last 10 years a number of prediction methods for 3D structures have been developed, first based on bioinformatics and data-mining, and more recently based on a coarse-grained physical representation of the systems. In this review we are going to present the challenges of RNA structure prediction and the main ideas behind bioinformatic approaches and physics-based approaches. We will focus on the description of the more recent physics-based phenomenological models and on how they are built to include the specificity of the interactions of RNA bases, whose role is critical in folding. Through examples from different models, we will point out the strengths of physics-based approaches, which are able not only to predict equilibrium structures, but also to investigate dynamical and thermodynamical behavior, and the open challenges to include more key interactions ruling RNA folding.
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Affiliation(s)
- Tristan Cragnolini
- Laboratoire de Biochimie Théorique UPR 9080 CNRS, Université Paris Diderot, Sorbonne, Paris Cité, IBPC 13 rue Pierre et Marie Curie, 75005 Paris, France
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17
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Cragnolini T, Laurin Y, Derreumaux P, Pasquali S. Coarse-Grained HiRE-RNA Model for ab Initio RNA Folding beyond Simple Molecules, Including Noncanonical and Multiple Base Pairings. J Chem Theory Comput 2015; 11:3510-22. [PMID: 26575783 DOI: 10.1021/acs.jctc.5b00200] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
HiRE-RNA is a coarse-grained model for RNA structure prediction and the dynamical study of RNA folding. Using a reduced set of particles and detailed interactions accounting for base-pairing and stacking, we show that noncanonical and multiple base interactions are necessary to capture the full physical behavior of complex RNAs. In this paper, we give a full account of the model and present results on the folding, stability, and free energy surfaces of 16 systems with 12 to 76 nucleotides of increasingly complex architectures, ranging from monomers to dimers, using a total of 850 μs of simulation time.
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Affiliation(s)
- Tristan Cragnolini
- Laboratoire de Biochimie Théorique UPR 9080 CNRS, Université Paris Diderot , Sorbonne, Paris Cité, IBPC 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Yoann Laurin
- Laboratoire de Biochimie Théorique UPR 9080 CNRS, Université Paris Diderot , Sorbonne, Paris Cité, IBPC 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique UPR 9080 CNRS, Université Paris Diderot , Sorbonne, Paris Cité, IBPC 13 rue Pierre et Marie Curie, 75005 Paris, France.,Institut Universitaire de France , Boulevard Saint-Michel, 75005 Paris, France
| | - Samuela Pasquali
- Laboratoire de Biochimie Théorique UPR 9080 CNRS, Université Paris Diderot , Sorbonne, Paris Cité, IBPC 13 rue Pierre et Marie Curie, 75005 Paris, France
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18
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Bowater RP, Cobb AM, Pivonkova H, Havran L, Fojta M. Biophysical and electrochemical studies of protein–nucleic acid interactions. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-014-1405-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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19
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Taxilaga-Zetina O, Pliego-Pastrana P, Carbajal-Tinoco MD. RNA pseudo-knots simulated with a one-bead coarse-grained model. J Chem Phys 2014; 140:115106. [PMID: 24655208 DOI: 10.1063/1.4868650] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We present a revised version of a Monte Carlo simulation model for RNA molecules that was introduced in a previous communication [O. Taxilaga-Zetina, P. Pliego-Pastrana, and M. D. Carbajal-Tinoco, Phys. Rev. E 81, 041914 (2010)]. The basic model consists of a series of knowledge-based pair potentials that were obtained from the statistical analysis of large RNAs belonging to the Protein Data Bank. These effective interactions are then used to dress a polymeric chain that reproduces relatively simple secondary structures (e.g., small hairpins). In order to describe more complicated three-dimensional structures such as pseudo-knots, here we include orientational information for the interaction between nucleotides forming hydrogen bonds, as in the case of the Watson-Crick base pairs. As a result, the simulated molecules obtained through the modified model are now consistent with their corresponding experimental configurations.
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Affiliation(s)
- Oscar Taxilaga-Zetina
- Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 México D.F., Mexico
| | - Patricia Pliego-Pastrana
- Área Académica de Matemáticas y Física, ICBI, Universidad Autónoma del Estado de Hidalgo, Carr. Pachuca Tulancingo Km 4.5, 42182 Pachuca Hgo., Mexico
| | - Mauricio D Carbajal-Tinoco
- Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 México D.F., Mexico
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20
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Badu SR, Melnik R, Paliy M, Prabhakar S, Sebetci A, Shapiro BA. Modeling of RNA nanotubes using molecular dynamics simulation. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:555-64. [PMID: 25208764 DOI: 10.1007/s00249-014-0985-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 08/14/2014] [Accepted: 08/21/2014] [Indexed: 01/11/2023]
Abstract
In this study, we construct novel RNA nanoclusters, RNA nanotubes made of several nanorings up to the size of 20 nm, utilizing the molecular dynamics simulation, and study their structural properties [i.e., the root mean square deviation, the radius of gyration and the radial distribution function (RDF)] in physiological solutions that can be used for drug delivery into the human body. The patterns of energy and temperature variations of the systems are also discussed. Furthermore, we study the concentration of ions around the tube as a function of time at a particular temperature. We have found that when the temperature increases, the number of ions increases within a certain distance of the tube. We report that the number of ions within this distance around the tubes decreases in quenched runs. This indicates that some ions evaporate with decrease in temperature, as has been observed in the case of the nanoring. RDF plots also demonstrate a similar trend with temperature, as was found in the case of RNA nanorings.
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Affiliation(s)
- S R Badu
- MS2Discovery Interdisciplinary Research Institute, M2Net Lab, Wilfrid Laurier University, 75 University Avenue, Waterloo, ON, N3L 3V6, Canada,
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21
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Novikova IV, Hennelly SP, Sanbonmatsu KY. Sizing up long non-coding RNAs: do lncRNAs have secondary and tertiary structure? BIOARCHITECTURE 2014; 2:189-99. [PMID: 23267412 PMCID: PMC3527312 DOI: 10.4161/bioa.22592] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Long noncoding RNAs (lncRNAs) play a key role in many important areas of epigenetics, stem cell biology, cancer, signaling and brain function. This emerging class of RNAs constitutes a large fraction of the transcriptome, with thousands of new lncRNAs reported each year. The molecular mechanisms of these RNAs are not well understood. Currently, very little structural data exist. We review the available lncRNA sequence and secondary structure data. Since almost no tertiary information is available for lncRNAs, we review crystallographic structures for other RNA systems and discuss the possibilities for lncRNAs in the context of existing constraints.
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22
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Chan CW, Chetnani B, Mondragón A. Structure and function of the T-loop structural motif in noncoding RNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:507-22. [PMID: 23754657 DOI: 10.1002/wrna.1175] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/10/2013] [Accepted: 04/26/2013] [Indexed: 12/22/2022]
Abstract
The T-loop is a frequently occurring five-nucleotide motif found in the structure of noncoding RNAs where it is commonly assumed to play an important role in stabilizing the tertiary RNA structure by facilitating long-range interactions between different regions of the molecule. T-loops were first identified in tRNA(Phe) and a formal consensus sequence for this motif was formulated and later revised based on analyses of the crystal structures of prokaryotic ribosomal RNAs and RNase P and the corresponding primary sequence of their orthologues. In the past decade, several new structures of large RNA molecules have been added to the RCSB Protein Data Bank, including the eukaryotic ribosome, a self-splicing group II intron, numerous synthetases in complex with their cognate transfer RNAs (tRNAs), transfer-messenger RNA (tmRNA) in complex with SmpB, several riboswitches, and a complex of bacterial RNase P bound to its tRNA substrate. In this review, the search for T-loops is extended to these new RNA molecules based on the previously established structure-based criteria. The review highlights and discusses the function and additional roles of T-loops in four broad categories of RNA molecules, namely tRNAs, ribosomal RNAs (rRNAs), P RNAs, and RNA genetic elements. Additionally, the potential application for T-loops as interaction modules is also discussed.
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Affiliation(s)
- Clarence W Chan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
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23
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Structural Characterization of the Internal Transcribed Spacer 2 (ITS2) of the Ribosomal DNA (rDNA) Cluster in Calyptratae (Diptera: Schizophora) and its Implications for Molecular Phylogenetic Analyses. J Mol Evol 2013; 76:158-71. [DOI: 10.1007/s00239-013-9548-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 01/30/2013] [Indexed: 10/27/2022]
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24
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Grabow WW, Zhuang Z, Shea JE, Jaeger L. The GA-minor submotif as a case study of RNA modularity, prediction, and design. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:181-203. [PMID: 23378290 DOI: 10.1002/wrna.1153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Complex natural RNAs such as the ribosome, group I and group II introns, and RNase P exemplify the fact that three-dimensional (3D) RNA structures are highly modular and hierarchical in nature. Tertiary RNA folding typically takes advantage of a rather limited set of recurrent structural motifs that are responsible for controlling bends or stacks between adjacent helices. Herein, the GA minor and related structural motifs are presented as a case study to highlight several structural and folding principles, to gain further insight into the structural evolution of naturally occurring RNAs, as well as to assist the rational design of artificial RNAs.
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Affiliation(s)
- Wade W Grabow
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
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25
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Ismer J, Rose AS, Tiemann JKS, Goede A, Rother K, Hildebrand PW. Voronoia4RNA--a database of atomic packing densities of RNA structures and their complexes. Nucleic Acids Res 2012; 41:D280-4. [PMID: 23161674 PMCID: PMC3531177 DOI: 10.1093/nar/gks1061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Voronoia4RNA (http://proteinformatics.charite.de/voronoia4rna/) is a structural database storing precalculated atomic volumes, atomic packing densities (PDs) and coordinates of internal cavities for currently 1869 RNAs and RNA-protein complexes. Atomic PDs are a measure for van der Waals interactions. Regions of low PD, containing water-sized internal cavities, refer to local structure flexibility or compressibility. RNA molecules build up the skeleton of large molecular machineries such as ribosomes or form smaller flexible structures such as riboswitches. The wealth of structural data on RNAs and their complexes allows setting up representative data sets and analysis of their structural features. We calculated atomic PDs from atomic volumes determined by the Voronoi cell method and internal cavities analytically by Delaunay triangulation. Reference internal PD values were derived from a non-redundant sub-data set of buried atoms. Comparison of internal PD values shows that RNA is more tightly packed than proteins. Finally, the relation between structure size, resolution and internal PD of the Voronoia4RNA entries is discussed. RNA, protein structures and their complexes can be visualized by the Jmol-based viewer Provi. Variations in PD are depicted by a color code. Internal cavities are represented by their molecular boundaries or schematically as balls.
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Affiliation(s)
- Jochen Ismer
- Charité, Institute of Medical Physics and Biophysics, Proteinformatics Group, Ziegelstr. 7/9, 10117, Berlin, Germany
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26
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Kirillova S, Carugo O. Hydration sites of unpaired RNA bases: a statistical analysis of the PDB structures. BMC STRUCTURAL BIOLOGY 2011; 11:41. [PMID: 22011380 PMCID: PMC3206426 DOI: 10.1186/1472-6807-11-41] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 10/19/2011] [Indexed: 11/10/2022]
Abstract
BACKGROUND Hydration is crucial for RNA structure and function. X-ray crystallography is the most commonly used method to determine RNA structures and hydration and, therefore, statistical surveys are based on crystallographic results, the number of which is quickly increasing. RESULTS A statistical analysis of the water molecule distribution in high-resolution X-ray structures of unpaired RNA nucleotides showed that: different bases have the same penchant to be surrounded by water molecules; clusters of water molecules indicate possible hydration sites, which, in some cases, match those of the major and minor grooves of RNA and DNA double helices; complex hydrogen bond networks characterize the solvation of the nucleotides, resulting in a significant rigidity of the base and its surrounding water molecules. Interestingly, the hydration sites around unpaired RNA bases do not match, in general, the positions that are occupied by the second nucleotide when the base-pair is formed. CONCLUSIONS The hydration sites around unpaired RNA bases were found. They do not replicate the atom positions of complementary bases in the Watson-Crick pairs.
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Affiliation(s)
- Svetlana Kirillova
- Department of Structural and Computational Biology, Max F, Perutz Laboratories, Vienna University, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
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27
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Daldrop P, Reyes FE, Robinson DA, Hammond CM, Lilley DM, Batey RT, Brenk R. Novel ligands for a purine riboswitch discovered by RNA-ligand docking. ACTA ACUST UNITED AC 2011; 18:324-35. [PMID: 21439477 PMCID: PMC3119931 DOI: 10.1016/j.chembiol.2010.12.020] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/02/2010] [Accepted: 12/29/2010] [Indexed: 01/01/2023]
Abstract
The increasing number of RNA crystal structures enables a structure-based approach to the discovery of new RNA-binding ligands. To develop the poorly explored area of RNA-ligand docking, we have conducted a virtual screening exercise for a purine riboswitch to probe the strengths and weaknesses of RNA-ligand docking. Using a standard protein-ligand docking program with only minor modifications, four new ligands with binding affinities in the micromolar range were identified, including two compounds based on molecular scaffolds not resembling known ligands. RNA-ligand docking performed comparably to protein-ligand docking indicating that this approach is a promising option to explore the wealth of RNA structures for structure-based ligand design.
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Affiliation(s)
- Peter Daldrop
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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28
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Pietropaolo A, Parrinello M. A quantitative measure of chirality inside nucleic acid databank. Chirality 2011; 23:534-42. [PMID: 21618614 DOI: 10.1002/chir.20961] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Accepted: 02/24/2011] [Indexed: 11/11/2022]
Abstract
We show the capability of a chirality index (Pietropaolo et al., Proteins 2008;70:667-677) to investigate nucleic acid structures because of its high sensitivity to helical conformations. By analyzing selected structures of DNA and RNA, we have found that sequences rich in cytosine and guanine have a tendency to left-handed chirality, in contrast to regions rich in adenine or thymine which show strong negative, right-handed, chirality values. We also analyze RNA structures, where specific loops and hairpin motifs are characterized by a well-defined chirality value. We find that in nucleosome the chirality is exalted, whereas in ribosome it is reduced. Our results illustrate the sensitivity of this descriptor for nucleic acid conformations.
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Affiliation(s)
- Adriana Pietropaolo
- Computational Science, Department of Chemistry and Applied Biosciences, ETH Zürich, USI Campus, Lugano, Switzerland.
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29
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Veeraraghavan N, Ganguly A, Chen JH, Bevilacqua PC, Hammes-Schiffer S, Golden BL. Metal binding motif in the active site of the HDV ribozyme binds divalent and monovalent ions. Biochemistry 2011; 50:2672-82. [PMID: 21348498 PMCID: PMC3068245 DOI: 10.1021/bi2000164] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The hepatitis delta virus (HDV) ribozyme uses both metal ion and nucleobase catalysis in its cleavage mechanism. A reverse G·U wobble was observed in a recent crystal structure of the precleaved state. This unusual base pair positions a Mg(2+) ion to participate in catalysis. Herein, we used molecular dynamics (MD) and X-ray crystallography to characterize the conformation and metal binding characteristics of this base pair in product and precleaved forms. Beginning with a crystal structure of the product form, we observed formation of the reverse G·U wobble during MD trajectories. We also demonstrated that this base pair is compatible with the diffraction data for the product-bound state. During MD trajectories of the product form, Na(+) ions interacted with the reverse G·U wobble in the RNA active site, and a Mg(2+) ion, introduced in certain trajectories, remained bound at this site. Beginning with a crystal structure of the precleaved form, the reverse G·U wobble with bound Mg(2+) remained intact during MD simulations. When we removed Mg(2+) from the starting precleaved structure, Na(+) ions interacted with the reverse G·U wobble. In support of the computational results, we observed competition between Na(+) and Mg(2+) in the precleaved ribozyme crystallographically. Nonlinear Poisson-Boltzmann calculations revealed a negatively charged patch near the reverse G·U wobble. This anionic pocket likely serves to bind metal ions and to help shift the pK(a) of the catalytic nucleobase, C75. Thus, the reverse G·U wobble motif serves to organize two catalytic elements, a metal ion and catalytic nucleobase, within the active site of the HDV ribozyme.
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Affiliation(s)
- Narayanan Veeraraghavan
- Huck Institutes of Life Sciences, 104 Chemistry Building, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Abir Ganguly
- Department of Chemistry, 104 Chemistry Building, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jui-Hui Chen
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, Indiana 47907
| | - Philip C. Bevilacqua
- Huck Institutes of Life Sciences, 104 Chemistry Building, The Pennsylvania State University, University Park, Pennsylvania 16802,Department of Chemistry, 104 Chemistry Building, The Pennsylvania State University, University Park, Pennsylvania 16802,To whom correspondence should be addressed. B.L.G.: telephone (765) 496-6165; fax (765) 494-7897; . S.H.-S. telephone (814) 865-6442; fax (814) 865-2927; . P.C.B. telephone (814) 863-3812; fax (814) 865-2927.
| | - Sharon Hammes-Schiffer
- Department of Chemistry, 104 Chemistry Building, The Pennsylvania State University, University Park, Pennsylvania 16802,To whom correspondence should be addressed. B.L.G.: telephone (765) 496-6165; fax (765) 494-7897; . S.H.-S. telephone (814) 865-6442; fax (814) 865-2927; . P.C.B. telephone (814) 863-3812; fax (814) 865-2927.
| | - Barbara L. Golden
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, Indiana 47907,To whom correspondence should be addressed. B.L.G.: telephone (765) 496-6165; fax (765) 494-7897; . S.H.-S. telephone (814) 865-6442; fax (814) 865-2927; . P.C.B. telephone (814) 863-3812; fax (814) 865-2927.
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30
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Abstract
RNA localisation is an important mode of delivering proteins to their site of function. Cis-acting signals within the RNAs, which can be thought of as zip-codes, determine the site of localisation. There are few examples of fully characterised RNA signals, but the signals are thought to be defined through a combination of primary, secondary, and tertiary structures. In this chapter, we describe a selection of computational methods for predicting RNA secondary structure, identifying localisation signals, and searching for similar localisation signals on a genome-wide scale. The chapter is aimed at the biologist rather than presenting the details of each of the individual methods.
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31
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Morris MJ, Negishi Y, Pazsint C, Schonhoft JD, Basu S. An RNA G-quadruplex is essential for cap-independent translation initiation in human VEGF IRES. J Am Chem Soc 2010; 132:17831-9. [PMID: 21105704 DOI: 10.1021/ja106287x] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
RNA G-quadruplexes located within the 5'-UTR of mRNA are almost always known to be associated with repression of cap-dependent translation. However, in this report we present functional as well as structural evidence that sequence redundancy in a G-rich segment within the 5'-UTR of human VEGF mRNA supports a 'switchable' RNA G-quadruplex structure that is essential for IRES-mediated translation initiation. Additionally, utilization of a specific combination of G-tracts within this segment allows for the conformational switch that implies a tunable regulatory role of the quadruplex structure in translation initiation. A sequence engineered from a functionally handicapped mutant moderately rescued the activity, further indicating the importance of G-quadruplex structure for VEGF IRES-A function. This to our knowledge is the first report of a conformationally flexible RNA G-quadruplex which is essential for IRES-mediated translation initiation.
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Affiliation(s)
- Mark J Morris
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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32
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Siegfried NA, Kierzek R, Bevilacqua PC. Role of unsatisfied hydrogen bond acceptors in RNA energetics and specificity. J Am Chem Soc 2010; 132:5342-4. [PMID: 20345162 DOI: 10.1021/ja9107726] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
RNA plays essential roles in much of biology. These functions are dictated by structures mediated by hydrogen bonding, stacking, electrostatics, and steric interactions. Roles of unsatisfied hydrogen bond functionalities in these structures are less well understood. Herein, we evaluated the energetic contributions of unsatisfied hydrogen bonding groups by placing chemically modified substituents in select internal positions in RNA helices and conducting thermodynamic studies. We find that unsatisfied carbonyl groups make exceptional contributions to structure formation (approximately 3 kcal/mol in free energy), most likely due to a combination of strain and dehydration effects. Thus, unsatisfied hydrogen bonding groups are likely key determinants in the folding energetics and specificity of many RNA and DNA molecules and may be especially important in tertiary structure interactions.
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Affiliation(s)
- Nathan A Siegfried
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Abstract
A series of coarse-grained models have been developed for study of the molecular dynamics of RNA nanostructures. The models in the series have one to three beads per nucleotide and include different amounts of detailed structural information. Such a treatment allows us to reach, for systems of thousands of nucleotides, a time scale of microseconds (i.e. by three orders of magnitude longer than in full atomistic modeling) and thus to enable simulations of large RNA polymers in the context of bionanotechnology. We find that the three-beads-per-nucleotide models, described by a set of just a few universal parameters, are able to describe different RNA conformations and are comparable in structural precision to the models where detailed values of the backbone P-C4' dihedrals taken from a reference structure are included. These findings are discussed in the context of RNA conformation classes.
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Affiliation(s)
- Maxim Paliy
- M2NeT Lab, Wilfrid Laurier University 75 University Avenue West Waterloo, ON, N2 L 3C5, Canada.
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Kirillova S, Tosatto SCE, Carugo O. FRASS: the web-server for RNA structural comparison. BMC Bioinformatics 2010; 11:327. [PMID: 20553602 PMCID: PMC2902451 DOI: 10.1186/1471-2105-11-327] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 06/16/2010] [Indexed: 11/24/2022] Open
Abstract
Background The impressive increase of novel RNA structures, during the past few years, demands automated methods for structure comparison. While many algorithms handle only small motifs, few techniques, developed in recent years, (ARTS, DIAL, SARA, SARSA, and LaJolla) are available for the structural comparison of large and intact RNA molecules. Results The FRASS web-server represents a RNA chain with its Gauss integrals and allows one to compare structures of RNA chains and to find similar entries in a database derived from the Protein Data Bank. We observed that FRASS scores correlate well with the ARTS and LaJolla similarity scores. Moreover, the-web server can also reproduce satisfactorily the DARTS classification of RNA 3D structures and the classification of the SCOR functions that was obtained by the SARA method. Conclusions The FRASS web-server can be easily used to detect relationships among RNA molecules and to scan efficiently the rapidly enlarging structural databases.
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Affiliation(s)
- Svetlana Kirillova
- Department of Structural and Computational Biology, Max F Perutz Laboratories, Vienna University, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
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Simeonov PL. Integral biomathics: A post-Newtonian view into the logos of bios. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2010; 102:85-121. [DOI: 10.1016/j.pbiomolbio.2010.01.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 01/29/2010] [Indexed: 11/29/2022]
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The transDSL ligase ribozyme can utilize various forms of modules to clamp its substrate and enzyme units. Biosci Biotechnol Biochem 2010; 74:872-4. [PMID: 20378973 DOI: 10.1271/bbb.90849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
TransDSL is an RNA ligase ribozyme whose enzyme unit joins two RNA fragments constituting a substrate. The enzyme unit recognizes the substrate by means of two clamp modules. We constructed active variants by replacing the original clamp module with various types of interactions. Such flexible modularity would be advantageous in the application of this ribozyme in nanobiotechnology.
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Ulyanov NB, James TL. RNA structural motifs that entail hydrogen bonds involving sugar-phosphate backbone atoms of RNA. NEW J CHEM 2010; 34:910-917. [PMID: 20689681 DOI: 10.1039/b9nj00754g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The growing number of high-resolution crystal structures of large RNA molecules provides much information for understanding the principles of structural organization of these complex molecules. Several in-depth analyses of nucleobase-centered RNA structural motifs and backbone conformations have been published based on this information, including a systematic classification of base pairs by Leontis and Westhof. However, hydrogen bonds involving sugar-phosphate backbone atoms of RNA have not been analyzed systematically until recently, although such hydrogen bonds appear to be common both in local and tertiary interactions. Here we review some backbone structural motifs discussed in the literature and analyze a set of eight high-resolution multi-domain RNA structures. The analyzed RNAs are highly structured: among 5372 nucleotides in this set, 89% are involved in at least one "long-range" RNA-RNA hydrogen bond, i.e., hydrogen bonds between atoms in the same residue or sequential residues are ignored. These long-range hydrogen bonds frequently use backbone atoms as hydrogen bond acceptors, i.e., OP1, OP2, O2', O3', O4', or O5', or as a donor (2'OH). A surprisingly large number of such hydrogen bonds are found, considering that neither single-stranded nor double-stranded regions will contain such hydrogen bonds unless additional interactions with other residues exist. Among 8327 long-range hydrogen bonds found in this set of structures, 2811, or about one-third, are hydrogen bonds entailing RNA backbone atoms; they involve 39% of all nucleotides in the structures. The majority of them (2111) are hydrogen bonds entailing ribose hydroxyl groups, which can be used either as a donor or an acceptor; they constitute 25% of all hydrogen bonds and involve 31% of all nucleotides. The phosphate oxygens OP1 or OP2 are used as hydrogen bond acceptors in 12% of all nucleotides, and the ribose ring oxygen O4' and phosphodiester oxygens O3' and O5' are used in 4%, 4%, and 1% of all nucleotides, respectively. Distributions of geometric parameters and some examples of such hydrogen bonds are presented in this report. A novel motif involving backbone hydrogen bonds, the ribose-phosphate zipper, is also identified.
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Affiliation(s)
- Nikolai B Ulyanov
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158-2517, USA
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Hutchinson EC, von Kirchbach JC, Gog JR, Digard P. Genome packaging in influenza A virus. J Gen Virol 2009; 91:313-28. [PMID: 19955561 DOI: 10.1099/vir.0.017608-0] [Citation(s) in RCA: 213] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The negative-sense RNA genome of influenza A virus is composed of eight segments, which encode 12 proteins between them. At the final stage of viral assembly, these genomic virion (v)RNAs are incorporated into the virion as it buds from the apical plasma membrane of the cell. Genome segmentation confers evolutionary advantages on the virus, but also poses a problem during virion assembly as at least one copy of each of the eight segments is required to produce a fully infectious virus particle. Historically, arguments have been presented in favour of a specific packaging mechanism that ensures incorporation of a full genome complement, as well as for an alternative model in which segments are chosen at random but packaged in sufficient numbers to ensure that a reasonable proportion of virions are viable. The question has seen a resurgence of interest in recent years leading to a consensus that the vast majority of virions contain no more than eight segments and that a specific mechanism does indeed function to select one copy of each vRNA. This review summarizes work leading to this conclusion. In addition, we describe recent progress in identifying the specific packaging signals and discuss likely mechanisms by which these RNA elements might operate.
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Affiliation(s)
- Edward C Hutchinson
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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Gong B, Chen JH, Yajima R, Chen Y, Chase E, Chadalavada DM, Golden BL, Carey PR, Bevilacqua PC. Raman crystallography of RNA. Methods 2009; 49:101-11. [PMID: 19409996 PMCID: PMC2753759 DOI: 10.1016/j.ymeth.2009.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 04/21/2009] [Accepted: 04/23/2009] [Indexed: 01/30/2023] Open
Abstract
Raman crystallography is the application of Raman spectroscopy to single crystals. This technique has been applied to a variety of protein molecules where it has provided unique information about biopolymer folding, substrate binding, and catalysis. Here, we describe the application of Raman crystallography to functional RNA molecules. RNA represents unique opportunities and challenges for Raman crystallography. One issue that confounds studies of RNA is its tendency to adopt multiple non-functional folds. Raman crystallography has the advantage that it isolates a single state of the RNA within the crystal and can evaluate its fold, metal ion binding properties (ligand identity, stoichiometry, and affinity), proton binding properties (identity, stoichiometry, and affinity), and catalytic potential. In particular, base-specific stretches can be identified and then associated with the binding of metal ions and protons. Because measurements are carried out in the hanging drop at ambient, rather than cryo, conditions and because RNA crystals tend to be approximately 70% solvent, RNA dynamics and conformational changes become experimentally accessible. This review focuses on experimental setup and procedures, acquisition and interpretation of Raman data, and determination of physicochemical properties of the RNA. Raman crystallographic and solution biochemical experiments on the HDV RNA enzyme are summarized and found to be in excellent agreement. Remarkably, characterization of the crystalline state has proven to help rather than hinder functional characterization of functional RNA, most likely because the tendency of RNA to fold heterogeneously is limited in a crystalline environment. Future applications of Raman crystallography to RNA are briefly discussed.
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Affiliation(s)
- Bo Gong
- Department of Biochemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Jui-Hui Chen
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, Indiana 47907
| | - Rieko Yajima
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - Yuanyuan Chen
- Department of Biochemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Elaine Chase
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, Indiana 47907
| | - Durga M. Chadalavada
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
| | - Barbara L. Golden
- Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, Indiana 47907
| | - Paul R. Carey
- Department of Biochemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Philip C. Bevilacqua
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802
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Paliy M, Melnik R, Shapiro BA. Molecular dynamics study of the RNA ring nanostructure: a phenomenon of self-stabilization. Phys Biol 2009; 6:046003. [PMID: 19741282 DOI: 10.1088/1478-3975/6/4/046003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We study mechanical and thermodynamic properties of RNA nanostructures focusing on a hexagonal nanoring discussed in Yingling and Shapiro (2007 Nano Lett. 7 2328). We are concerned with the following main issues: (i) the stability of the nanoring versus temperature; (ii) the effect of the environment (solvent, counterions) on its stability; (iii) conformations and dynamics under external force. The process of evaporation of the ions from the ring upon temperature drop has been found, demonstrating a surprising feature-the uptake of ions by the nanoring increases with the temperature. The connection of this behavior to the dielectric constant of water, hydration and structural changes in the nanoring is discussed. Several properties of the nanoring, such as elastic and transport coefficients, have been determined. A measure of the tensile elasticity of the ring against its uniform 2D in-plane compression has been given, as K(eff) < or = 0.01 GPa, which is a much lower value compared to typical values found for soft matter other than RNA.
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Affiliation(s)
- Maxim Paliy
- Wilfrid Laurier University, West Waterloo, ON, Canada
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Takeda R, Ding B. Viroid intercellular trafficking: RNA motifs, cellular factors and broad impacts. Viruses 2009; 1:210-21. [PMID: 21994546 PMCID: PMC3185492 DOI: 10.3390/v1020210] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 08/31/2009] [Accepted: 09/01/2009] [Indexed: 12/30/2022] Open
Abstract
Viroids are noncoding RNAs that infect plants. In order to establish systemic infection, these RNAs must traffic from an initially infected host cell into neighboring cells and ultimately throughout a whole plant. Recent studies have identified structural motifs in a viroid that are required for trafficking, enabling further studies on the mechanisms of their function. Some cellular proteins interact with viroids in vivo and may play a role in viroid trafficking, which can now be directly tested by using a virus-induced gene silencing system that functions efficiently in plant species from which these factors were identified. This review discusses these recent advances, unanswered questions and the use of viroid infection as an highly productive model to elucidate mechanisms of RNA trafficking that is of broad biological significance.
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Affiliation(s)
- Ryuta Takeda
- Department of Plant Cellular and Molecular Biology and Molecular, Cellular and Developmental Biology Program, Ohio State University, 207 Rightmire Hall, 1060 Carmack Road, Columbus, 43210 USA; E-Mail:
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Laing C, Jung S, Iqbal A, Schlick T. Tertiary motifs revealed in analyses of higher-order RNA junctions. J Mol Biol 2009; 393:67-82. [PMID: 19660472 DOI: 10.1016/j.jmb.2009.07.089] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/29/2009] [Accepted: 07/29/2009] [Indexed: 12/22/2022]
Abstract
RNA junctions are secondary-structure elements formed when three or more helices come together. They are present in diverse RNA molecules with various fundamental functions in the cell. To better understand the intricate architecture of three-dimensional (3D) RNAs, we analyze currently solved 3D RNA junctions in terms of base-pair interactions and 3D configurations. First, we study base-pair interaction diagrams for solved RNA junctions with 5 to 10 helices and discuss common features. Second, we compare these higher-order junctions to those containing 3 or 4 helices and identify global motif patterns such as coaxial stacking and parallel and perpendicular helical configurations. These analyses show that higher-order junctions organize their helical components in parallel and helical configurations similar to lower-order junctions. Their sub-junctions also resemble local helical configurations found in three- and four-way junctions and are stabilized by similar long-range interaction preferences such as A-minor interactions. Furthermore, loop regions within junctions are high in adenine but low in cytosine, and in agreement with previous studies, we suggest that coaxial stacking between helices likely forms when the common single-stranded loop is small in size; however, other factors such as stacking interactions involving noncanonical base pairs and proteins can greatly determine or disrupt coaxial stacking. Finally, we introduce the ribo-base interactions: when combined with the along-groove packing motif, these ribo-base interactions form novel motifs involved in perpendicular helix-helix interactions. Overall, these analyses suggest recurrent tertiary motifs that stabilize junction architecture, pack helices, and help form helical configurations that occur as sub-elements of larger junction networks. The frequent occurrence of similar helical motifs suggest nature's finite and perhaps limited repertoire of RNA helical conformation preferences. More generally, studies of RNA junctions and tertiary building blocks can ultimately help in the difficult task of RNA 3D structure prediction.
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Affiliation(s)
- Christian Laing
- Department of Chemistry, New York University, 251 Mercer Street, New York, NY 10012, USA
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Huggins W, Ghosh SK, Wollenzien P. Hydrogen bonding and packing density are factors most strongly connected to limiting sites of high flexibility in the 16S rRNA in the 30S ribosome. BMC STRUCTURAL BIOLOGY 2009; 9:49. [PMID: 19643000 PMCID: PMC2731775 DOI: 10.1186/1472-6807-9-49] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 07/30/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND Conformational flexibility in structured RNA frequently is critical to function. The 30S ribosomal subunit exists in different conformations in different functional states due to changes in the central part of the 16S rRNA. We are interested in evaluating the factors that might be responsible for restricting flexibility to specific parts of the 16S rRNA using biochemical data obtained from the 30S subunit in solution. This problem was approached taking advantage of the observation that there must be a high degree of conformational flexibility at sites where UV photocrosslinking occurs and a lack of flexibility inhibits photoreactivity at many other sites that are otherwise suitable for reaction. RESULTS We used 30S x-ray structures to quantify the properties of the nucleotide pairs at UV- and UVA-s4U-induced photocrosslinking sites in 16S rRNA and compared these to the properties of many hundreds of additional sites that have suitable geometry but do not undergo photocrosslinking. Five factors that might affect RNA flexibility were investigated - RNA interactions with ribosomal proteins, interactions with Mg2+ ions, the presence of long-range A minor motif interactions, hydrogen bonding and the count of neighboring heavy atoms around the center of each nucleobase to estimate the neighbor packing density. The two factors that are very different in the unreactive inflexible pairs compared to the reactive ones are the average number of hydrogen bonds and the average value for the number of neighboring atoms. In both cases, these factors are greater for the unreactive nucleotide pairs at a statistically very significant level. CONCLUSION The greater extent of hydrogen bonding and neighbor atom density in the unreactive nucleotide pairs is consistent with reduced flexibility at a majority of the unreactive sites. The reactive photocrosslinking sites are clustered in the 30S subunit and this indicates nonuniform patterns of hydrogen bonding and packing density in the 16S rRNA tertiary structure. Because this analysis addresses inter-nucleotide distances and geometry between nucleotides distant in the primary sequence, the results indicate regional and global flexibility of the rRNA.
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Affiliation(s)
- Wayne Huggins
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, USA
- RTI International, Research Triangle Park, USA
| | - Sujit K Ghosh
- Department of Statistics, North Carolina State University, Raleigh, USA
| | - Paul Wollenzien
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, USA
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Analysis of four-way junctions in RNA structures. J Mol Biol 2009; 390:547-59. [PMID: 19445952 DOI: 10.1016/j.jmb.2009.04.084] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/21/2009] [Accepted: 04/30/2009] [Indexed: 11/24/2022]
Abstract
RNA secondary structures can be divided into helical regions composed of canonical Watson-Crick and related base pairs, as well as single-stranded regions such as hairpin loops, internal loops, and junctions. These elements function as building blocks in the design of diverse RNA molecules with various fundamental functions in the cell. To better understand the intricate architecture of three-dimensional (3D) RNAs, we analyze existing RNA four-way junctions in terms of base-pair interactions and 3D configurations. Specifically, we identify nine broad junction families according to coaxial stacking patterns and helical configurations. We find that helices within junctions tend to arrange in roughly parallel and perpendicular patterns and stabilize their conformations using common tertiary motifs such as coaxial stacking, loop-helix interaction, and helix packing interaction. Our analysis also reveals a number of highly conserved base-pair interaction patterns and novel tertiary motifs such as A-minor-coaxial stacking combinations and sarcin/ricin motif variants. Such analyses of RNA building blocks can ultimately help in the difficult task of RNA 3D structure prediction.
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Fauzi H, Agyeman A, Hines JV. T box transcription antitermination riboswitch: influence of nucleotide sequence and orientation on tRNA binding by the antiterminator element. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1789:185-91. [PMID: 19152843 PMCID: PMC2656570 DOI: 10.1016/j.bbagrm.2008.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 11/18/2022]
Abstract
Many bacteria utilize riboswitch transcription regulation to monitor and appropriately respond to cellular levels of important metabolites or effector molecules. The T box transcription antitermination riboswitch responds to cognate uncharged tRNA by specifically stabilizing an antiterminator element in the 5'-untranslated mRNA leader region and precluding formation of a thermodynamically more stable terminator element. Stabilization occurs when the tRNA acceptor end base pairs with the first four nucleotides in the seven nucleotide bulge of the highly conserved antiterminator element. The significance of the conservation of the antiterminator bulge nucleotides that do not base pair with the tRNA is unknown, but they are required for optimal function. In vitro selection was used to determine if the isolated antiterminator bulge context alone dictates the mode in which the tRNA acceptor end binds the bulge nucleotides. No sequence conservation beyond complementarity was observed and the location was not constrained to the first four bases of the bulge. The results indicate that formation of a structure that recognizes the tRNA acceptor end in isolation is not the determinant driving force for the high phylogenetic sequence conservation observed within the antiterminator bulge. Additional factors or T box leader features more likely influenced the phylogenetic sequence conservation.
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Affiliation(s)
- Hamid Fauzi
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, 45701, USA
| | - Akwasi Agyeman
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, 45701, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
| | - Jennifer V. Hines
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, 45701, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
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Blouin S, Craggs TD, Lafontaine DA, Penedo JC. Functional studies of DNA-protein interactions using FRET techniques. Methods Mol Biol 2009; 543:475-502. [PMID: 19378182 DOI: 10.1007/978-1-60327-015-1_28] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein-DNA interactions underpin life and play key roles in all cellular processes and functions including DNA transcription, packaging, replication, and repair. Identifying and examining the nature of these interactions is therefore a crucial prerequisite to understand the molecular basis of how these fundamental processes take place. The application of fluorescence techniques and in particular fluorescence resonance energy transfer (FRET) to provide structural and kinetic information has experienced a stunning growth during the past decade. This has been mostly promoted by new advances in the preparation of dye-labeled nucleic acids and proteins and in optical sensitivity, where its implementation at the level of individual molecules has opened a new biophysical frontier. Nowadays, the application of FRET-based techniques to the analysis of protein-DNA interactions spans from the classical steady-state and time-resolved methods averaging over large ensembles to the analysis of distances, conformational changes, and enzymatic reactions in individual Protein-DNA complexes. This chapter introduces the practical aspects of applying these methods for the study of Protein-DNA interactions.
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Affiliation(s)
- Simon Blouin
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, QC, Canada, J1K 2R1
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Djelloul M, Denise A. Automated motif extraction and classification in RNA tertiary structures. RNA (NEW YORK, N.Y.) 2008; 14:2489-2497. [PMID: 18957493 PMCID: PMC2590963 DOI: 10.1261/rna.1061108] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 08/15/2008] [Indexed: 05/27/2023]
Abstract
We used a novel graph-based approach to extract RNA tertiary motifs. We cataloged them all and clustered them using an innovative graph similarity measure. We applied our method to three widely studied structures: Haloarcula marismortui 50S (H.m 50S), Escherichia coli 50S (E. coli 50S), and Thermus thermophilus 16S (T.th 16S) RNAs. We identified 10 known motifs without any prior knowledge of their shapes or positions. We additionally identified four putative new motifs.
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Affiliation(s)
- Mahassine Djelloul
- Laboratoire de Recherche en Informatique, Université Paris-Sud 11 and CNRS, 91405 Orsay Cedex, France
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Jaeger L, Verzemnieks EJ, Geary C. The UA_handle: a versatile submotif in stable RNA architectures. Nucleic Acids Res 2008; 37:215-30. [PMID: 19036788 PMCID: PMC2615604 DOI: 10.1093/nar/gkn911] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Stable RNAs are modular and hierarchical 3D architectures taking advantage of recurrent structural motifs to form extensive non-covalent tertiary interactions. Sequence and atomic structure analysis has revealed a novel submotif involving a minimal set of five nucleotides, termed the UA_handle motif (5'XU/AN(n)X3'). It consists of a U:A Watson-Crick: Hoogsteen trans base pair stacked over a classic Watson-Crick base pair, and a bulge of one or more nucleotides that can act as a handle for making different types of long-range interactions. This motif is one of the most versatile building blocks identified in stable RNAs. It enters into the composition of numerous recurrent motifs of greater structural complexity such as the T-loop, the 11-nt receptor, the UAA/GAN and the G-ribo motifs. Several structural principles pertaining to RNA motifs are derived from our analysis. A limited set of basic submotifs can account for the formation of most structural motifs uncovered in ribosomal and stable RNAs. Structural motifs can act as structural scaffoldings and be functionally and topologically equivalent despite sequence and structural differences. The sequence network resulting from the structural relationships shared by these RNA motifs can be used as a proto-language for assisting prediction and rational design of RNA tertiary structures.
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Affiliation(s)
- Luc Jaeger
- Chemistry and Biochemistry Department, University of California, Santa Barbara, CA 93106-9510, USA.
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