1
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Sabalette KB, Makarova L, Marcia M. G·U base pairing motifs in long non-coding RNAs. Biochimie 2023; 214:123-140. [PMID: 37353139 DOI: 10.1016/j.biochi.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/25/2023]
Abstract
Long non-coding RNAs (lncRNAs) are recently-discovered transcripts involved in gene expression regulation and associated with diseases. Despite the unprecedented molecular complexity of these transcripts, recent studies of the secondary and tertiary structure of lncRNAs are starting to reveal the principles of lncRNA structural organization, with important functional implications. It therefore starts to be possible to analyze lncRNA structures systematically. Here, using a set of prototypical and medically-relevant lncRNAs of known secondary structure, we specifically catalogue the distribution and structural environment of one of the first-identified and most frequently occurring non-canonical Watson-Crick interactions, the G·U base pair. We compare the properties of G·U base pairs in our set of lncRNAs to those of the G·U base pairs in other well-characterized transcripts, like rRNAs, tRNAs, ribozymes, and riboswitches. Furthermore, we discuss how G·U base pairs in these targets participate in establishing interactions with proteins or miRNAs, and how they enable lncRNA tertiary folding by forming intramolecular or metal-ion interactions. Finally, by identifying highly-G·U-enriched regions of yet unknown function in our target lncRNAs, we provide a new rationale for future experimental investigation of these motifs, which will help obtain a more comprehensive understanding of lncRNA functions and molecular mechanisms in the future.
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Affiliation(s)
- Karina Belen Sabalette
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs, Grenoble, 38042, France
| | - Liubov Makarova
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs, Grenoble, 38042, France
| | - Marco Marcia
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs, Grenoble, 38042, France.
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2
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Westhof E, Watson ZL, Zirbel CL, Cate JHD. Anionic G•U pairs in bacterial ribosomal rRNAs. RNA (NEW YORK, N.Y.) 2023; 29:1069-1076. [PMID: 37068913 DOI: 10.1261/rna.079583.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/05/2023] [Indexed: 06/18/2023]
Abstract
Wobble GU pairs (or G•U) occur frequently within double-stranded RNA helices interspersed between standard G=C and A-U Watson-Crick pairs. Another type of G•U pair interacting via their Watson-Crick edges has been observed in the A site of ribosome structures between a modified U34 in the tRNA anticodon triplet and G + 3 in the mRNA. In such pairs, the electronic structure of the U is changed with a negative charge on N3(U), resulting in two H-bonds between N1(G)…O4(U) and N2(G)…N3(U). Here, we report that such pairs occur in other highly conserved positions in ribosomal RNAs of bacteria in the absence of U modification. An anionic cis Watson-Crick G•G pair is also observed and well conserved in the small subunit. These pairs are observed in tightly folded regions.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de biologie moléculaire et cellulaire du CNRS, F-67084 Strasbourg, France
| | - Zoe L Watson
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, USA
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, Ohio 43403, USA
| | - Jamie H D Cate
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, California 94720, USA
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3
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Fröhlking T, Mlýnský V, Janeček M, Kührová P, Krepl M, Banáš P, Šponer J, Bussi G. Automatic Learning of Hydrogen-Bond Fixes in the AMBER RNA Force Field. J Chem Theory Comput 2022; 18:4490-4502. [PMID: 35699952 PMCID: PMC9281393 DOI: 10.1021/acs.jctc.2c00200] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
The
capability of
current force fields to reproduce RNA structural
dynamics is limited. Several methods have been developed to take advantage
of experimental data in order to enforce agreement with experiments.
Here, we extend an existing framework which allows arbitrarily chosen
force-field correction terms to be fitted by quantification of the
discrepancy between observables back-calculated from simulation and
corresponding experiments. We apply a robust regularization protocol
to avoid overfitting and additionally introduce and compare a number
of different regularization strategies, namely, L1, L2, Kish size,
relative Kish size, and relative entropy penalties. The training set
includes a GACC tetramer as well as more challenging systems, namely,
gcGAGAgc and gcUUCGgc RNA tetraloops. Specific intramolecular hydrogen
bonds in the AMBER RNA force field are corrected with automatically
determined parameters that we call gHBfixopt. A validation
involving a separate simulation of a system present in the training
set (gcUUCGgc) and new systems not seen during training (CAAU and
UUUU tetramers) displays improvements regarding the native population
of the tetraloop as well as good agreement with NMR experiments for
tetramers when using the new parameters. Then, we simulate folded
RNAs (a kink–turn and L1 stalk rRNA) including hydrogen bond
types not sufficiently present in the training set. This allows a
final modification of the parameter set which is named gHBfix21 and
is suggested to be applicable to a wider range of RNA systems.
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Affiliation(s)
- Thorben Fröhlking
- Scuola Internazionale Superiore di Studi Avanzati, via Bonomea 265, Trieste 34136, Italy
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic
| | - Michal Janeček
- Department of Physical Chemistry, Faculty of Science, Palacky University, tr. 17 listopadu 12, Olomouc 771 46, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University Olomouc, Slechtitelu 27, 779 00 Olomouc, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University Olomouc, Slechtitelu 27, 779 00 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University Olomouc, Slechtitelu 27, 779 00 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University Olomouc, Slechtitelu 27, 779 00 Olomouc, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, via Bonomea 265, Trieste 34136, Italy
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4
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Westhof E, Thornlow B, Chan PP, Lowe TM. Eukaryotic tRNA sequences present conserved and amino acid-specific structural signatures. Nucleic Acids Res 2022; 50:4100-4112. [PMID: 35380696 PMCID: PMC9023262 DOI: 10.1093/nar/gkac222] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/16/2022] [Accepted: 03/22/2022] [Indexed: 11/18/2022] Open
Abstract
Metazoan organisms have many tRNA genes responsible for decoding amino acids. The set of all tRNA genes can be grouped in sets of common amino acids and isoacceptor tRNAs that are aminoacylated by corresponding aminoacyl-tRNA synthetases. Analysis of tRNA alignments shows that, despite the high number of tRNA genes, specific tRNA sequence motifs are highly conserved across multicellular eukaryotes. The conservation often extends throughout the isoacceptors and isodecoders with, in some cases, two sets of conserved isodecoders. This study is focused on non-Watson–Crick base pairs in the helical stems, especially GoU pairs. Each of the four helical stems may contain one or more conserved GoU pairs. Some are amino acid specific and could represent identity elements for the cognate aminoacyl tRNA synthetases. Other GoU pairs are found in more than a single amino acid and could be critical for native folding of the tRNAs. Interestingly, some GoU pairs are anticodon-specific, and others are found in phylogenetically-specific clades. Although the distribution of conservation likely reflects a balance between accommodating isotype-specific functions as well as those shared by all tRNAs essential for ribosomal translation, such conservations may indicate the existence of specialized tRNAs for specific translation targets, cellular conditions, or alternative functions.
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Affiliation(s)
- Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR 9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Bryan Thornlow
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Patricia P Chan
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Todd M Lowe
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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5
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Kasprzak WK, Ahmed NA, Shapiro BA. Modeling ligand docking to RNA in the design of RNA-based nanostructures. Curr Opin Biotechnol 2020; 63:16-25. [DOI: 10.1016/j.copbio.2019.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/30/2019] [Indexed: 12/30/2022]
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6
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Wu J, Zhou C, Li J, Li C, Tao X, Leontis NB, Zirbel CL, Bisaro DM, Ding B. Functional analysis reveals G/U pairs critical for replication and trafficking of an infectious non-coding viroid RNA. Nucleic Acids Res 2020; 48:3134-3155. [PMID: 32083649 PMCID: PMC7102988 DOI: 10.1093/nar/gkaa100] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/03/2020] [Accepted: 02/18/2020] [Indexed: 01/19/2023] Open
Abstract
While G/U pairs are present in many RNAs, the lack of molecular studies to characterize the roles of multiple G/U pairs within a single RNA limits our understanding of their biological significance. From known RNA 3D structures, we observed that the probability a G/U will form a Watson-Crick (WC) base pair depends on sequence context. We analyzed 17 G/U pairs in the 359-nucleotide genome of Potato spindle tuber viroid (PSTVd), a circular non-coding RNA that replicates and spreads systemically in host plants. Most putative G/U base pairs were experimentally supported by selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). Deep sequencing PSTVd genomes from plants inoculated with a cloned master sequence revealed naturally occurring variants, and showed that G/U pairs are maintained to the same extent as canonical WC base pairs. Comprehensive mutational analysis demonstrated that nearly all G/U pairs are critical for replication and/or systemic spread. Two selected G/U pairs were found to be required for PSTVd entry into, but not for exit from, the host vascular system. This study identifies critical roles for G/U pairs in the survival of an infectious RNA, and increases understanding of structure-based regulation of replication and trafficking of pathogen and cellular RNAs.
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Affiliation(s)
- Jian Wu
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Cuiji Zhou
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA
| | - James Li
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Chun Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaorong Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Neocles B Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - David M Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Biao Ding
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, USA.,Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210, USA
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7
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Stacking geometry between two sheared Watson-Crick basepairs: Computational chemistry and bioinformatics based prediction. Biochim Biophys Acta Gen Subj 2020; 1864:129600. [PMID: 32179130 DOI: 10.1016/j.bbagen.2020.129600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/05/2020] [Accepted: 03/11/2020] [Indexed: 11/21/2022]
Abstract
BACKGROUND Molecular modeling of RNA double helices is possible using most probable values of basepair parameters obtained from crystal structure database. The A:A w:wC non-canonical basepair, involving Watson-Crick edges of two Adenines in cis orientation, appears quite frequently in database. Bimodal distribution of its Shear, due to two different H-bonding schemes, introduces the confusion in assigning most the probable value. Its effect is pronounced when the A:A w:wC basepair stacks on Sheared wobble G:U W:WC basepairs. METHODS We employed molecular dynamics simulations of three possible double helices with GAG, UAG and GAU sequence motifs at their centers and quantum chemical calculation for non-canonical A:A w:wC basepair stacked on G:U W:WC basepair. RESULTS We noticed stable structures of GAG motif with specifically negative Shear of the A:A basepair but stabilities of the other motifs were not found with A:A w:wC basepairing. Hybrid DFT-D and MP2 stacking energy analyses on dinucleotide step sequences, A:A w:wC::G:U W:WC and A:A w:wC::U:G W:WC reveal that viable orientation of A:A::G:U prefers one of the H-bonding modes with negative Shear, supported by crystal structure database. The A:A::U:G dinucleotide, however, prefers structure with only positive Shear. CONCLUSIONS The quantum chemical calculations explain why MD simulations of GAG sequence motif only appear stable. In the cases of the GAU and UAG motifs "tug of war" situation between positive and negative Shears of A:A w:wC basepair induces conformational plasticity. GENERAL SIGNIFICANCE We have projected comprehensive reason behind the promiscuous nature of A:A w:wC basepair which brings occasional structural plasticity.
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8
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Zhang X, Cao Y, Zhang W, Simmons MP. Adenine·cytosine substitutions are an alternative pathway of compensatory mutation in angiosperm ITS2. RNA (NEW YORK, N.Y.) 2020; 26:209-217. [PMID: 31748405 PMCID: PMC6961544 DOI: 10.1261/rna.072660.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/14/2019] [Indexed: 06/01/2023]
Abstract
Compensatory mutations are crucial for functional RNA because they maintain RNA configuration and thus function. Compensatory mutation has traditionally been considered to be a two-step substitution through the GU-base-pair intermediate. We tested for an alternative AC-mediated compensatory mutation (ACCM). We investigated ACCMs by using a comprehensive sampling of ribosomal internal transcribed spacer 2 (ITS2) from 3934 angiosperm species in 80 genera and 55 families. We predicted ITS2 consensus secondary structures by using LocARNA for structure-based alignment and partitioning paired and unpaired regions. We examined and compared the substitution rates and frequencies among base pairs by using RNA-specific models. Base-pair states of ACCMs were mapped onto the inferred phylogenetic trees to infer their evolution. All types of compensatory mutations involving the AC intermediate were observed, but the most frequent substitutions were with AU or GC pairs, which are part of the AU-AC-GC pathway. Compared with the GU intermediate, AC had a lower frequency and higher mutability. Within the AU-AC-GC pathway, the AU-AC substitution rate was much slower than the AC-GC substitution rate. No consistently higher overall rate was identified for either pathway among all 80 sampled lineages, though compensatory mutations through the AC intermediate averaged about half that through the GU intermediate. These results demonstrate an alternative compensatory mutation between AU and GC that helps address the controversial inference of inferred simultaneous double substitutions.
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Affiliation(s)
- Xinwan Zhang
- Marine College, Shandong University, Weihai 264209, China
| | - Yong Cao
- Marine College, Shandong University, Weihai 264209, China
| | - Wei Zhang
- Marine College, Shandong University, Weihai 264209, China
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Mark P Simmons
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523, USA
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9
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Hosseini M, Roy P, Sissler M, Zirbel CL, Westhof E, Leontis N. How to fold and protect mitochondrial ribosomal RNA with fewer guanines. Nucleic Acids Res 2019; 46:10946-10968. [PMID: 30215760 PMCID: PMC6237812 DOI: 10.1093/nar/gky762] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 09/06/2018] [Indexed: 01/25/2023] Open
Abstract
Mammalian mitochondrial ribosomes evolved from bacterial ribosomes by reduction of ribosomal RNAs, increase of ribosomal protein content, and loss of guanine nucleotides. Guanine is the base most sensitive to oxidative damage. By systematically comparing high-quality, small ribosomal subunit RNA sequence alignments and solved 3D ribosome structures from mammalian mitochondria and bacteria, we deduce rules for folding a complex RNA with the remaining guanines shielded from solvent. Almost all conserved guanines in both bacterial and mammalian mitochondrial ribosomal RNA form guanine-specific, local or long-range, RNA–RNA or RNA–protein interactions. Many solvent-exposed guanines conserved in bacteria are replaced in mammalian mitochondria by bases less sensitive to oxidation. New guanines, conserved only in the mitochondrial alignment, are strategically positioned at solvent inaccessible sites to stabilize the ribosomal RNA structure. New mitochondrial proteins substitute for truncated RNA helices, maintain mutual spatial orientations of helices, compensate for lost RNA–RNA interactions, reduce solvent accessibility of bases, and replace guanines conserved in bacteria by forming specific amino acid–RNA interactions.
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Affiliation(s)
- Maryam Hosseini
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Poorna Roy
- Center for RNA Biomedicine, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Marie Sissler
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg France
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Eric Westhof
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg France
| | - Neocles Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
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10
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Wang E, Sun H, Wang J, Wang Z, Liu H, Zhang JZH, Hou T. End-Point Binding Free Energy Calculation with MM/PBSA and MM/GBSA: Strategies and Applications in Drug Design. Chem Rev 2019; 119:9478-9508. [DOI: 10.1021/acs.chemrev.9b00055] [Citation(s) in RCA: 578] [Impact Index Per Article: 115.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ercheng Wang
- Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Huiyong Sun
- Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Junmei Wang
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Zhe Wang
- Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hui Liu
- Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - John Z. H. Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, Shanghai Key Laboratory of Green Chemistry & Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- NYU−ECNU Center for Computational Chemistry, NYU Shanghai, Shanghai 200122, China
- Department of Chemistry, New York University, New York, New York 10003, United States
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Tingjun Hou
- Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
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11
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Westhof E, Yusupov M, Yusupova G. The multiple flavors of GoU pairs in RNA. J Mol Recognit 2019; 32:e2782. [PMID: 31033092 PMCID: PMC6617799 DOI: 10.1002/jmr.2782] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/02/2019] [Accepted: 03/14/2019] [Indexed: 11/10/2022]
Abstract
Wobble GU pairs (or GoU) occur frequently within double‐stranded RNA helices interspersed within the standard G═C and A─U Watson‐Crick pairs. However, other types of GoU pairs interacting on their Watson‐Crick edges have been observed. The structural and functional roles of such alternative GoU pairs are surprisingly diverse and reflect the various pairings G and U can form by exploiting all the subtleties of their electronic configurations. Here, the structural characteristics of the GoU pairs are updated following the recent crystallographic structures of functional ribosomal complexes and the development in our understanding of ribosomal translation.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Marat Yusupov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
| | - Gulnara Yusupova
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
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12
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Šponer J, Bussi G, Krepl M, Banáš P, Bottaro S, Cunha RA, Gil-Ley A, Pinamonti G, Poblete S, Jurečka P, Walter NG, Otyepka M. RNA Structural Dynamics As Captured by Molecular Simulations: A Comprehensive Overview. Chem Rev 2018; 118:4177-4338. [PMID: 29297679 PMCID: PMC5920944 DOI: 10.1021/acs.chemrev.7b00427] [Citation(s) in RCA: 336] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Indexed: 12/14/2022]
Abstract
With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Department of Biology , University of Copenhagen , Copenhagen 2200 , Denmark
| | - Richard A Cunha
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Giovanni Pinamonti
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Simón Poblete
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
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13
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Sripathi KN, Banáš P, Réblová K, Šponer J, Otyepka M, Walter NG. Wobble pairs of the HDV ribozyme play specific roles in stabilization of active site dynamics. Phys Chem Chem Phys 2015; 17:5887-900. [PMID: 25631765 DOI: 10.1039/c4cp05083e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The hepatitis delta virus (HDV) is the only known human pathogen whose genome contains a catalytic RNA motif (ribozyme). The overall architecture of the HDV ribozyme is that of a double-nested pseudoknot, with two GU pairs flanking the active site. Although extensive studies have shown that mutation of either wobble results in decreased catalytic activity, little work has focused on linking these mutations to specific structural effects on catalytic fitness. Here we use molecular dynamics simulations based on an activated structure to probe the active site dynamics as a result of wobble pair mutations. In both wild-type and mutant ribozymes, the in-line fitness of the active site (as a measure of catalytic proficiency) strongly depends on the presence of a C75(N3H3+)N1(O5') hydrogen bond, which positions C75 as the general acid for the reaction. Our mutational analyses show that each GU wobble supports catalytically fit conformations in distinct ways; the reverse G25U20 wobble promotes high in-line fitness, high occupancy of the C75(N3H3+)G1(O5') general-acid hydrogen bond and stabilization of the G1U37 wobble, while the G1U37 wobble acts more locally by stabilizing high in-line fitness and the C75(N3H3+)G1(O5') hydrogen bond. We also find that stable type I A-minor and P1.1 hydrogen bonding above and below the active site, respectively, prevent local structural disorder from spreading and disrupting global conformation. Taken together, our results define specific, often redundant architectural roles for several structural motifs of the HDV ribozyme active site, expanding the known roles of these motifs within all HDV-like ribozymes and other structured RNAs.
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Affiliation(s)
- Kamali N Sripathi
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1065, USA
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14
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Sweeney BA, Roy P, Leontis NB. An introduction to recurrent nucleotide interactions in RNA. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 6:17-45. [PMID: 25664365 DOI: 10.1002/wrna.1258] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
RNA secondary structure diagrams familiar to molecular biologists summarize at a glance the folding of RNA chains to form Watson–Crick paired double helices. However, they can be misleading: First of all, they imply that the nucleotides in loops and linker segments, which can amount to 35% to 50% of a structured RNA, do not significantly interact with other nucleotides. Secondly, they give the impression that RNA molecules are loosely organized in three-dimensional (3D) space. In fact, structured RNAs are compactly folded as a result of numerous long-range, sequence-specific interactions, many of which involve loop or linker nucleotides. Here, we provide an introduction for students and researchers of RNA on the types, prevalence, and sequence variations of inter-nucleotide interactions that structure and stabilize RNA 3D motifs and architectures, using Escherichia coli (E. coli) 16S ribosomal RNA as a concrete example. The picture that emerges is that almost all nucleotides in structured RNA molecules, including those in nominally single-stranded loop or linker regions, form specific interactions that stabilize functional structures or mediate interactions with other molecules. The small number of noninteracting, ‘looped-out’ nucleotides make it possible for the RNA chain to form sharp turns. Base-pairing is the most specific interaction in RNA as it involves edge-to-edge hydrogen bonding (H-bonding) of the bases. Non-Watson–Crick base pairs are a significant fraction (30% or more) of base pairs in structured RNAs.
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15
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Cannone JJ, Sweeney BA, Petrov AI, Gutell RR, Zirbel CL, Leontis N. R3D-2-MSA: the RNA 3D structure-to-multiple sequence alignment server. Nucleic Acids Res 2015; 43:W15-23. [PMID: 26048960 PMCID: PMC4489222 DOI: 10.1093/nar/gkv543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/09/2015] [Indexed: 01/01/2023] Open
Abstract
The RNA 3D Structure-to-Multiple Sequence Alignment Server (R3D-2-MSA) is a new web service that seamlessly links RNA three-dimensional (3D) structures to high-quality RNA multiple sequence alignments (MSAs) from diverse biological sources. In this first release, R3D-2-MSA provides manual and programmatic access to curated, representative ribosomal RNA sequence alignments from bacterial, archaeal, eukaryal and organellar ribosomes, using nucleotide numbers from representative atomic-resolution 3D structures. A web-based front end is available for manual entry and an Application Program Interface for programmatic access. Users can specify up to five ranges of nucleotides and 50 nucleotide positions per range. The R3D-2-MSA server maps these ranges to the appropriate columns of the corresponding MSA and returns the contents of the columns, either for display in a web browser or in JSON format for subsequent programmatic use. The browser output page provides a 3D interactive display of the query, a full list of sequence variants with taxonomic information and a statistical summary of distinct sequence variants found. The output can be filtered and sorted in the browser. Previous user queries can be viewed at any time by resubmitting the output URL, which encodes the search and re-generates the results. The service is freely available with no login requirement at http://rna.bgsu.edu/r3d-2-msa.
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Affiliation(s)
- Jamie J Cannone
- Institute for Cellular and Molecular Biology, and the Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, TX 78712, USA
| | - Blake A Sweeney
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Anton I Petrov
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Robin R Gutell
- Institute for Cellular and Molecular Biology, and the Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, TX 78712, USA
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Neocles Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
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16
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Abstract
RNA molecules are highly modular components that can be used in a variety of contexts for building new metabolic, regulatory and genetic circuits in cells. The majority of synthetic RNA systems to date predominately rely on two-dimensional modularity. However, a better understanding and integration of three-dimensional RNA modularity at structural and functional levels is critical to the development of more complex, functional bio-systems and molecular machines for synthetic biology applications.
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Affiliation(s)
- Wade Grabow
- Department of Chemistry and Biochemistry, Seattle Pacific University3307 Third Avenue West, Seattle, WA 98119USA
| | - Luc Jaeger
- Department of Chemistry and Biochemistry, Bio-Molecular Science and Engineering Program, University of CaliforniaSanta Barbara, CA 93106-9510USA
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17
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Kondo J, Dock-Bregeon AC, Willkomm DK, Hartmann RK, Westhof E. Structure of an A-form RNA duplex obtained by degradation of 6S RNA in a crystallization droplet. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:634-9. [PMID: 23722840 PMCID: PMC3668581 DOI: 10.1107/s1744309113013018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/13/2013] [Indexed: 12/29/2022]
Abstract
In the course of a crystallographic study of a 132 nt variant of Aquifex aeolicus 6S RNA, a crystal structure of an A-form RNA duplex containing 12 base pairs was solved at a resolution of 2.6 Å. In fact, the RNA duplex is part of the 6S RNA and was obtained by accidental but precise degradation of the 6S RNA in a crystallization droplet. 6S RNA degradation was confirmed by microscopic observation of crystals and gel electrophoresis of crystallization droplets. The RNA oligomers obtained form regular A-form duplexes containing three GoU wobble-type base pairs, one of which engages in intermolecular contacts through a ribose-zipper motif at the crystal-packing interface.
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Affiliation(s)
- Jiro Kondo
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan.
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18
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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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19
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Panigrahi S, Pal R, Bhattacharyya D. Structure and energy of non-canonical basepairs: comparison of various computational chemistry methods with crystallographic ensembles. J Biomol Struct Dyn 2012; 29:541-56. [PMID: 22066539 DOI: 10.1080/07391102.2011.10507404] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Different types of non-canonical basepairs, in addition to the Watson-Crick ones, are observed quite frequently in RNA. Their importance in the three dimensional structure is not fully understood, but their various roles have been proposed by different groups. We have analyzed the energetics and geometry of 32 most frequently observed basepairs in the functional RNA crystal structures using different popular empirical, semi-empirical and ab initio quantum chemical methods and compared their optimized geometry with the crystal data. These basepairs are classified into three categories: polar, non-polar and sugar-mediated, depending on the types of atoms involved in hydrogen bonding. In case of polar basepairs, most of the methods give rise to optimized structures close to their initial geometry. The interaction energies also follow similar trends, with the polar ones having more attractive interaction energies. Some of the C-H...O/N hydrogen bond mediated non-polar basepairs are also found to be significantly stable in terms of their interaction energy values. Few polar basepairs, having amino or carboxyl groups not hydrogen bonded to anything, such as G:G H:W C, show large flexibility. Most of the non-polar basepairs, except A:G s:s T and A:G w:s C, are found to be stable; indicating C-H...O/N interaction also plays a prominent role in stabilizing the basepairs. The sugar mediated basepairs show variability in their structures, due to the involvement of flexible ribose sugar. These presumably indicate that the most of the polar basepairs along with few non-polar ones act as seed for RNA folding while few may act as some conformational switch in the RNA.
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Affiliation(s)
- Swati Panigrahi
- Biophysics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
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20
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Grabow WW, Zhuang Z, Swank ZN, Shea JE, Jaeger L. The right angle (RA) motif: a prevalent ribosomal RNA structural pattern found in group I introns. J Mol Biol 2012; 424:54-67. [PMID: 22999957 DOI: 10.1016/j.jmb.2012.09.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/11/2012] [Accepted: 09/12/2012] [Indexed: 12/16/2022]
Abstract
The right angle (RA) motif, previously identified in the ribosome and used as a structural module for nano-construction, is a recurrent structural motif of 13 nucleotides that establishes a 90° bend between two adjacent helices. Comparative sequence analysis was used to explore the sequence space of the RA motif within ribosomal RNAs in order to define its canonical sequence space signature. We investigated the sequence constraints associated with the RA signature using several artificial self-assembly systems. Thermodynamic and topological investigations of sequence variants associated with the RA motif in both minimal and expanded structural contexts reveal that the presence of a helix at the 3' end of the RA motif increases the thermodynamic stability and rigidity of the resulting three-helix junction domain. A search for the RA in naturally occurring RNAs as well as its experimental characterization led to the identification of the RA in groups IC1 and ID intron ribozymes, where it is suggested to play an integral role in stabilizing peripheral structural domains. The present study exemplifies the need of empirical analysis of RNA structural motifs for facilitating the rational design and structure prediction of RNAs.
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Affiliation(s)
- Wade W Grabow
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
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21
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Mooers BHM, Singh A. The crystal structure of an oligo(U):pre-mRNA duplex from a trypanosome RNA editing substrate. RNA (NEW YORK, N.Y.) 2011; 17:1870-1883. [PMID: 21878548 PMCID: PMC3185919 DOI: 10.1261/rna.2880311] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 07/30/2011] [Indexed: 05/31/2023]
Abstract
Guide RNAs bind antiparallel to their target pre-mRNAs to form editing substrates in reaction cycles that insert or delete uridylates (Us) in most mitochondrial transcripts of trypanosomes. The 5' end of each guide RNA has an anchor sequence that binds to the pre-mRNA by base-pair complementarity. The template sequence in the middle of the guide RNA directs the editing reactions. The 3' ends of most guide RNAs have ∼15 contiguous Us that bind to the purine-rich unedited pre-mRNA upstream of the editing site. The resulting U-helix is rich in G·U wobble base pairs. To gain insights into the structure of the U-helix, we crystallized 8 bp of the U-helix in one editing substrate for the A6 mRNA of Trypanosoma brucei. The fragment provides three samples of the 5'-AGA-3'/5'-UUU-3' base-pair triple. The fusion of two identical U-helices head-to-head promoted crystallization. We obtained X-ray diffraction data with a resolution limit of 1.37 Å. The U-helix had low and high twist angles before and after each G·U wobble base pair; this variation was partly due to shearing of the wobble base pairs as revealed in comparisons with a crystal structure of a 16-nt RNA with all Watson-Crick base pairs. Both crystal structures had wider major grooves at the junction between the poly(U) and polypurine tracts. This junction mimics the junction between the template helix and the U-helix in RNA-editing substrates and may be a site of major groove invasion by RNA editing proteins.
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Affiliation(s)
- Blaine H M Mooers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104-5419, USA.
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22
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Caisová L, Marin B, Melkonian M. A close-up view on ITS2 evolution and speciation - a case study in the Ulvophyceae (Chlorophyta, Viridiplantae). BMC Evol Biol 2011; 11:262. [PMID: 21933414 PMCID: PMC3225284 DOI: 10.1186/1471-2148-11-262] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 09/20/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The second Internal Transcriber Spacer (ITS2) is a fast evolving part of the nuclear-encoded rRNA operon located between the 5.8S and 28S rRNA genes. Based on crossing experiments it has been proposed that even a single Compensatory Base Change (CBC) in helices 2 and 3 of the ITS2 indicates sexual incompatibility and thus separates biological species. Taxa without any CBC in these ITS2 regions were designated as a 'CBC clade'. However, in depth comparative analyses of ITS2 secondary structures, ITS2 phylogeny, the origin of CBCs, and their relationship to biological species have rarely been performed. To gain 'close-up' insights into ITS2 evolution, (1) 86 sequences of ITS2 including secondary structures have been investigated in the green algal order Ulvales (Chlorophyta, Viridiplantae), (2) after recording all existing substitutions, CBCs and hemi-CBCs (hCBCs) were mapped upon the ITS2 phylogeny, rather than merely comparing ITS2 characters among pairs of taxa, and (3) the relation between CBCs, hCBCs, CBC clades, and the taxonomic level of organisms was investigated in detail. RESULTS High sequence and length conservation allowed the generation of an ITS2 consensus secondary structure, and introduction of a novel numbering system of ITS2 nucleotides and base pairs. Alignments and analyses were based on this structural information, leading to the following results: (1) in the Ulvales, the presence of a CBC is not linked to any particular taxonomic level, (2) most CBC 'clades' sensu Coleman are paraphyletic, and should rather be termed CBC grades. (3) the phenetic approach of pairwise comparison of sequences can be misleading, and thus, CBCs/hCBCs must be investigated in their evolutionary context, including homoplasy events (4) CBCs and hCBCs in ITS2 helices evolved independently, and we found no evidence for a CBC that originated via a two-fold hCBC substitution. CONCLUSIONS Our case study revealed several discrepancies between ITS2 evolution in the Ulvales and generally accepted assumptions underlying ITS2 evolution as e.g. the CBC clade concept. Therefore, we developed a suite of methods providing a critical 'close-up' view into ITS2 evolution by directly tracing the evolutionary history of individual positions, and we caution against a non-critical use of the ITS2 CBC clade concept for species delimitation.
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Affiliation(s)
- Lenka Caisová
- Universität zu Köln, Biozentrum Köln, Botanisches Institut, Zülpicher Str. 47b, 50674 Köln, Germany.
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23
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Zgarbová M, Jurečka P, Banáš P, Otyepka M, Sponer JE, Leontis NB, Zirbel CL, Sponer J. Noncanonical hydrogen bonding in nucleic acids. Benchmark evaluation of key base-phosphate interactions in folded RNA molecules using quantum-chemical calculations and molecular dynamics simulations. J Phys Chem A 2011; 115:11277-92. [PMID: 21910417 DOI: 10.1021/jp204820b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
RNA molecules are stabilized by a wide range of noncanonical interactions that are not present in DNA. Among them, the recently classified base-phosphate (BPh) interactions belong to the most important ones. Twelve percent of nucleotides in the ribosomal crystal structures are involved in BPh interactions. BPh interactions are highly conserved and provide major constraints on RNA sequence evolution. Here we provide assessment of the energetics of BPh interactions using MP2 computations extrapolated to the complete basis set of atomic orbitals and corrected for higher-order electron correlation effects. The reference computations are compared with DFT-D and DFT-D3 approaches, the SAPT method, and the molecular mechanics force field. The computations, besides providing the basic benchmark for the BPh interactions, allow some refinements of the original classification, including identification of some potential doubly bonded BPh patterns. The reference computations are followed by analysis of some larger RNA fragments that consider the context of the BPh interactions. The computations demonstrate the complexity of interaction patterns utilizing the BPh interactions in real RNA structures. The BPh interactions are often involved in intricate interaction networks. We studied BPh interactions of protonated adenine that can contribute to catalysis of hairpin ribozyme, the key BPh interaction in the S-turn motif of the sarcin-ricin loop, which may predetermine the S-turn topology and complex BPh patterns from the glmS riboswitch. Finally, the structural stability of BPh interactions in explicit solvent molecular dynamics simulations is assessed. The simulations well preserve key BPh interactions and allow dissection of structurally/functionally important water-meditated BPh bridges, which could not be considered in earlier bioinformatics classification of BPh interactions.
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Affiliation(s)
- Marie Zgarbová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, Olomouc, Czech Republic
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24
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Šponer J, Šponer JE, Petrov AI, Leontis NB. Quantum chemical studies of nucleic acids: can we construct a bridge to the RNA structural biology and bioinformatics communities? J Phys Chem B 2010; 114:15723-41. [PMID: 21049899 PMCID: PMC4868365 DOI: 10.1021/jp104361m] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this feature article, we provide a side-by-side introduction for two research fields: quantum chemical calculations of molecular interaction in nucleic acids and RNA structural bioinformatics. Our main aim is to demonstrate that these research areas, while largely separated in contemporary literature, have substantial potential to complement each other that could significantly contribute to our understanding of the exciting world of nucleic acids. We identify research questions amenable to the combined application of modern ab initio methods and bioinformatics analysis of experimental structures while also assessing the limitations of these approaches. The ultimate aim is to attain valuable physicochemical insights regarding the nature of the fundamental molecular interactions and how they shape RNA structures, dynamics, function, and evolution.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic
| | - Judit E. Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic
| | - Anton I. Petrov
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Neocles B. Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
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25
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Spacková N, Réblová K, Sponer J. Structural dynamics of the box C/D RNA kink-turn and its complex with proteins: the role of the A-minor 0 interaction, long-residency water bridges, and structural ion-binding sites revealed by molecular simulations. J Phys Chem B 2010; 114:10581-93. [PMID: 20701388 DOI: 10.1021/jp102572k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Kink-turns (K-turns) are recurrent elbow-like RNA motifs that participate in protein-assisted RNA folding and contribute to RNA dynamics. We carried out a set of molecular dynamics (MD) simulations using parm99 and parmbsc0 force fields to investigate structural dynamics of the box C/D RNA and its complexes with two proteins: native archaeal L7ae protein and human 15.5 kDa protein, originally bound to very similar structure of U4 snRNA. The box C/D RNA forms K-turn with A-minor 0 tertiary interaction between its canonical (C) and noncanonical (NC) stems. The local K-turn architecture is thus different from the previously studied ribosomal K-turns 38 and 42 having A-minor I interaction. The simulations reveal visible structural dynamics of this tertiary interaction involving altogether six substates which substantially contribute to the elbow-like flexibility of the K-turn. The interaction can even temporarily shift to the A-minor I type pattern; however, this is associated with distortion of the G/A base pair in the NC-stem of the K-turn. The simulations show reduction of the K-turn flexibility upon protein binding. The protein interacts with the apex of the K-turn and with the NC-stem. The protein-RNA interface includes long-residency hydration sites. We have also found long-residency hydration sites and major ion-binding sites associated with the K-turn itself. The overall topology of the K-turn remains stable in all simulations. However, in simulations of free K-turn, we observed instability of the key C16(O2')-A7(N1) H-bond, which is a signature interaction of K-turns and which was visibly more stable in simulations of K-turns possessing A-minor I interaction. It may reflect either some imbalance of the force field or it may be a correct indication of early stages of unfolding since this K-turn requires protein binding for its stabilization. Interestingly, the 16(O2')-7(N1) H- bond is usually not fully lost since it is replaced by a water bridge with a tightly bound water, which is adenine-specific similarly as the original interaction. The 16(O2')-7(N1) H-bond is stabilized by protein binding. The stabilizing effect is more visible with the human 15.5 kDa protein, which is attributed to valine to arginine substitution in the binding site. The behavior of the A-minor interaction is force-field-dependent because the parmbsc0 force field attenuates the A-minor fluctuations compared to parm99 simulations. Behavior of other regions of the box C/D RNA is not sensitive to the force field choice. Simulation with net-neutralizing Na(+) and 0.2 M excess salt conditions appear in all aspects equivalent. The simulations show loss of a hairpin tetraloop, which is not part of the K-turn. This was attributed to force field limitations.
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Affiliation(s)
- Nad'a Spacková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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26
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Gagnon MG, Boutorine YI, Steinberg SV. Recurrent RNA motifs as probes for studying RNA-protein interactions in the ribosome. Nucleic Acids Res 2010; 38:3441-53. [PMID: 20139416 PMCID: PMC2879513 DOI: 10.1093/nar/gkq031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To understand how the nucleotide sequence of ribosomal RNA determines its tertiary structure, we developed a new approach for identification of those features of rRNA sequence that are responsible for formation of different short- and long-range interactions. The approach is based on the co-analysis of several examples of a particular recurrent RNA motif. For different cases of the motif, we design combinatorial gene libraries in which equivalent nucleotide positions are randomized. Through in vivo expression of the designed libraries we select those variants that provide for functional ribosomes. Then, analysis of the nucleotide sequences of the selected clones would allow us to determine the sequence constraints imposed on each case of the motif. The constraints shared by all cases are interpreted as providing for the integrity of the motif, while those ones specific for individual cases would enable the motif to fit into the particular structural context. Here we demonstrate the validity of this approach for three examples of the so-called along-groove packing motif found in different parts of ribosomal RNA.
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Affiliation(s)
- Matthieu G Gagnon
- Département de Biochimie, Université de Montréal, Montréal, CP 6128, Succursale Centre-Ville, QC H3C 3J7, Canada
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27
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Gagnon MG, Steinberg SV. The adenosine wedge: a new structural motif in ribosomal RNA. RNA (NEW YORK, N.Y.) 2010; 16:375-81. [PMID: 20038632 PMCID: PMC2811666 DOI: 10.1261/rna.1550310] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Here, we present a new recurrent RNA arrangement, the so-called adenosine wedge (A-wedge), which is found in three places of the ribosomal RNA in both ribosomal subunits. The arrangement has a hierarchical structure, consisting of elements previously described as recurrent motifs, namely, the along-groove packing motif, the A-minor and the hook-turn. Within the A-wedge, these elements are involved in different types of cause-effect relationships, providing together for the particular tertiary structure of the motif.
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Affiliation(s)
- Matthieu G Gagnon
- Departement de Biochimie, Universite de Montreal, Montreal, Quebec H3C 3J7, Canada
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28
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Réblová K, Střelcová Z, Kulhánek P, Beššeová I, Mathews DH, Van Nostrand K, Yildirim I, Turner DH, Šponer J. An RNA Molecular Switch: Intrinsic Flexibility of 23S rRNA Helices 40 and 68 5′-UAA/5′-GAN Internal Loops Studied by Molecular Dynamics Methods. J Chem Theory Comput 2010; 6:910-29. [DOI: 10.1021/ct900440t] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kamila Réblová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Zora Střelcová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Petr Kulhánek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Ivana Beššeová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - David H. Mathews
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Keith Van Nostrand
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Ilyas Yildirim
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Douglas H. Turner
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic, Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, and Department of Chemistry, University of
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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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Réblová K, Střelcová Z, Kulhánek P, Beššeová I, Mathews DH, Nostrand KV, Yildirim I, Turner DH, Šponer J. An RNA molecular switch: Intrinsic flexibility of 23S rRNA Helices 40 and 68 5'-UAA/5'-GAN internal loops studied by molecular dynamics methods. J Chem Theory Comput 2010; 2010:910-929. [PMID: 21132104 PMCID: PMC2994019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Functional RNA molecules such as ribosomal RNAs frequently contain highly conserved internal loops with a 5'-UAA/5'-GAN (UAA/GAN) consensus sequence. The UAA/GAN internal loops adopt distinctive structure inconsistent with secondary structure predictions. The structure has a narrow major groove and forms a trans Hoogsteen/Sugar edge (tHS) A/G base pair followed by an unpaired stacked adenine, a trans Watson-Crick/Hoogsteen (tWH) U/A base pair and finally by a bulged nucleotide (N). The structure is further stabilized by a three-adenine stack and base-phosphate interaction. In the ribosome, the UAA/GAN internal loops are involved in extensive tertiary contacts, mainly as donors of A-minor interactions. Further, this sequence can adopt an alternative 2D/3D pattern stabilized by a four-adenine stack involved in a smaller number of tertiary interactions. The solution structure of an isolated UAA/GAA internal loop shows substantially rearranged base pairing with three consecutive non-Watson-Crick base pairs. Its A/U base pair adopts an incomplete cis Watson-Crick/Sugar edge (cWS) A/U conformation instead of the expected Watson-Crick arrangement. We performed 3.1 µs of explicit solvent molecular dynamics (MD) simulations of the X-ray and NMR UAA/GAN structures, supplemented by MM-PBSA free energy calculations, locally enhanced sampling (LES) runs, targeted MD (TMD) and nudged elastic band (NEB) analysis. We compared parm99 and parmbsc0 force fields and net-neutralizing Na(+) vs. excess salt KCl ion environments. Both force fields provide a similar description of the simulated structures, with the parmbsc0 leading to modest narrowing of the major groove. The excess salt simulations also cause a similar effect. While the NMR structure is entirely stable in simulations, the simulated X-ray structure shows considerable widening of the major groove, loss of base-phosphate interaction and other instabilities. The alternative X-ray geometry even undergoes conformational transition towards the solution 2D structure. Free energy calculations confirm that the X-ray arrangement is less stable than the solution structure. LES, TMD and NEB provide a rather consistent pathway for interconversion between the X-ray and NMR structures. In simulations, the incomplete cWS A/U base pair of the NMR structure is water mediated and alternates with the canonical A-U base pair, which is not indicated by the NMR data. Completion of full cWS A/U base pair is prevented by the overall internal loop arrangement. In summary, the simulations confirm that the UAA/GAN internal loop is a molecular switch RNA module that adopts its functional geometry upon specific tertiary contexts.
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Affiliation(s)
- Kamila Réblová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic
| | - Zora Střelcová
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Petr Kulhánek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Ivana Beššeová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic
| | - David H. Mathews
- Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642
| | - Keith Van Nostrand
- Department of Biochemistry & Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 712, Rochester, New York 14642
| | - Ilyas Yildirim
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627
| | - Douglas H. Turner
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic
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31
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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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Zirbel CL, Sponer JE, Sponer J, Stombaugh J, Leontis NB. Classification and energetics of the base-phosphate interactions in RNA. Nucleic Acids Res 2009; 37:4898-918. [PMID: 19528080 PMCID: PMC2731888 DOI: 10.1093/nar/gkp468] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Structured RNA molecules form complex 3D architectures stabilized by multiple interactions involving the nucleotide base, sugar and phosphate moieties. A significant percentage of the bases in structured RNA molecules in the Protein Data Bank (PDB) hydrogen-bond with phosphates of other nucleotides. By extracting and superimposing base-phosphate (BPh) interactions from a reduced-redundancy subset of 3D structures from the PDB, we identified recurrent phosphate-binding sites on the RNA bases. Quantum chemical calculations were carried out on model systems representing each BPh interaction. The calculations show that the centers of each cluster obtained from the structure superpositions correspond to energy minima on the potential energy hypersurface. The calculations also show that the most stable phosphate-binding sites occur on the Watson-Crick edge of guanine and the Hoogsteen edge of cytosine. We modified the 'Find RNA 3D' (FR3D) software suite to automatically find and classify BPh interactions. Comparison of the 3D structures of the 16S and 23S rRNAs of Escherichia coli and Thermus thermophilus revealed that most BPh interactions are phylogenetically conserved and they occur primarily in hairpin, internal or junction loops or as part of tertiary interactions. Bases that form BPh interactions, which are conserved in the rRNA 3D structures are also conserved in homologous rRNA sequence alignments.
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Affiliation(s)
- Craig L Zirbel
- Department of Mathematics and Statistics, Center for Biomolecular Sciences, Bowling Green State University, Bowling Green, OH 43403, USA
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33
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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: 83] [Impact Index Per Article: 5.5] [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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Mládek A, Sharma P, Mitra A, Bhattacharyya D, Sponer J, Sponer JE. Trans Hoogsteen/sugar edge base pairing in RNA. Structures, energies, and stabilities from quantum chemical calculations. J Phys Chem B 2009; 113:1743-55. [PMID: 19152254 DOI: 10.1021/jp808357m] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Trans Hoogsteen/sugar edge (H/SE) RNA base pairs form one of the six families of RNA base pairs that utilize the 2'-hydroxyl group of ribose for base pairing and play key roles in stabilizing folded RNA molecules. Here, we provide a detailed quantum chemical characterization of intrinsic structures and interaction energies of this base pair family, along with the evaluation of solvent screening effects by a continuum solvent approach. We report DFT-optimized geometries and MP2 interaction energies for all 10 crystallographically identified members of the family, for a representative set of them, using complete basis set extrapolation. For 6 of the 10 base pairs, we had to apply geometric constraints to keep the geometries relevant to RNA. We confirm that the remaining, hitherto undetected, possible members of this family do not have appropriate steric features required to establish stable base pairing in the trans H/SE fashion. The interaction patterns in the trans H/SE family are highly diverse, with gas-phase interaction energies in the range from -1 to -17 kcal/mol. Except for the C/rC and G/rG trans H/SE base pairs, the interaction energy is roughly evenly distributed between the HF and correlation components. Thus, in the trans H/SE base pairs, the relative importance of electron correlation is noticeably smaller than in the cis WC/SE or cis and trans SE/SE base pairs, but still larger than in canonical base pairs. The trans H/SE A/rG base pair is the intrinsically most stable member of this family. This base pair is also known as the sheared AG base pair and belongs to the most prominent set of RNA base pairs utilized in molecular building blocks of functional RNAs. For all trans H/SE base pairs that we identified, in addition to conventional base pairing, viable alternative structures were stabilized by amino-acceptor interactions. In the QM calculations, these amino-acceptor complexes appear to be equally as stable as those with common H-bonds, and more importantly, the switch to amino-acceptor interaction does not require any significant geometrical rearrangement of the base pairs. Such interactions are worthy of further investigations, as X-ray crystallography cannot unambiguously distinguish between conventional and amino-acceptor interactions involving the 2'-hydroxyl group, formation of such interactions is usually not considered, and molecular modeling force fields do not include such interactions properly as a result of neglect of aminogroup pyramidalization.
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Affiliation(s)
- Arnost Mládek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
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Šponer J, Zgarbová M, Jurečka P, Riley KE, Šponer JE, Hobza P. Reference Quantum Chemical Calculations on RNA Base Pairs Directly Involving the 2′-OH Group of Ribose. J Chem Theory Comput 2009; 5:1166-79. [DOI: 10.1021/ct800547k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Marie Zgarbová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Petr Jurečka
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Kevin E. Riley
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Judit E. Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Pavel Hobza
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
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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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37
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Nasalean L, Stombaugh J, Zirbel CL, Leontis NB. RNA 3D Structural Motifs: Definition, Identification, Annotation, and Database Searching. NON-PROTEIN CODING RNAS 2008. [DOI: 10.1007/978-3-540-70840-7_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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38
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Davis AR, Znosko BM. Thermodynamic characterization of naturally occurring RNA single mismatches with G-U nearest neighbors. Biochemistry 2008; 47:10178-87. [PMID: 18754680 DOI: 10.1021/bi800471z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Due to their prevalence and roles in biological systems, single mismatches adjacent to G-U pairs are important RNA structural elements. Since there are only limited experimental values for the stability of single mismatches adjacent to G-U pairs, current algorithms using free energy minimization to predict RNA secondary structure from sequence assign predicted thermodynamic values to these types of single mismatches. Here, thermodynamic data are reported for frequently occurring single mismatches adjacent to at least one G-U pair. This experimental data can be used in place of predicted thermodynamic values in algorithms that predict secondary structure from sequence using free energy minimization. When predicting the thermodynamic contributions of previously unmeasured single mismatches, most algorithms apply the same thermodynamic penalty for an A-U pair adjacent to a single mismatch and a G-U pair adjacent to a single mismatch. A recent study, however, suggests that the penalty for a G-U pair adjacent to a tandem mismatch should be 1.2 +/- 0.1 kcal/mol, and the penalty for an A-U pair adjacent to a tandem mismatch should be 0.5 +/- 0.2 kcal/mol [Christiansen, M. E. and Znosko, B. M. (2008) Biochemistry 47, 4329-4336]. Therefore, the data reported here are combined with the existing thermodynamic dataset of single mismatches, and nearest neighbor parameters are derived for an A-U pair adjacent to a single mismatch (1.1 +/- 0.1 kcal/mol) and a G-U pair adjacent to a single mismatch (1.4 +/- 0.1 kcal/mol).
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Affiliation(s)
- Amber R Davis
- Department of Chemistry, Saint Louis University, Saint Louis, Missouri 63103, USA
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39
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Mokdad A, Frankel AD. ISFOLD: structure prediction of base pairs in non-helical RNA motifs from isostericity signatures in their sequence alignments. J Biomol Struct Dyn 2008; 25:467-72. [PMID: 18282001 DOI: 10.1080/07391102.2008.10531239] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The existence and identity of non-Watson-Crick base pairs (bps) within RNA bulges, internal loops, and hairpin loops cannot reliably be predicted by existing algorithms. We have developed the Isfold (Isosteric Folding) program as a tool to examine patterns of nucleotide substitutions from sequence alignments or mutation experiments and identify plausible bp interactions. We infer these interactions based on the observation that each non-Watson-Crick bp has a signature pattern of isosteric substitutions where mutations can be made that preserve the 3D structure. Isfold produces a dynamic representation of predicted bps within defined motifs in order of their probabilities. The software was developed under Windows XP, and is capable of running on PC and MAC with Matlab 7.1 (SP3) or higher. A PC stand-alone version that does not require Matlab also is available. This software and a user manual are freely available at www.ucsf.edu/frankel/isfold.
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Affiliation(s)
- Ali Mokdad
- Department of Biochemistry and Biophysics, University of California at San Francisco, 600 16th Street, San Francisco, CA 94143-2280, USA.
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40
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Smirnov A, Tarassov I, Mager-Heckel AM, Letzelter M, Martin RP, Krasheninnikov IA, Entelis N. Two distinct structural elements of 5S rRNA are needed for its import into human mitochondria. RNA (NEW YORK, N.Y.) 2008; 14:749-59. [PMID: 18314502 PMCID: PMC2271358 DOI: 10.1261/rna.952208] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
RNA import into mitochondria is a widespread phenomenon. Studied in details for yeast, protists, and plants, it still awaits thorough investigation for human cells, in which the nuclear DNA-encoded 5S rRNA is imported. Only the general requirements for this pathway have been described, whereas specific protein factors needed for 5S rRNA delivery into mitochondria and its structural determinants of import remain unknown. In this study, a systematic analysis of the possible role of human 5S rRNA structural elements in import was performed. Our experiments in vitro and in vivo show that two distinct regions of the human 5S rRNA molecule are needed for its mitochondrial targeting. One of them is located in the proximal part of the helix I and contains a conserved uncompensated G:U pair. The second and most important one is associated with the loop E-helix IV region with several noncanonical structural features. Destruction or even destabilization of these sites leads to a significant decrease of the 5S rRNA import efficiency. On the contrary, the beta-domain of the 5S rRNA was proven to be dispensable for import, and thus it can be deleted or substituted without affecting the 5S rRNA importability. This finding was used to demonstrate that the 5S rRNA can function as a vector for delivering heterologous RNA sequences into human mitochondria. 5S rRNA-based vectors containing a substitution of a part of the beta-domain by a foreign RNA sequence were shown to be much more efficiently imported in vivo than the wild-type 5S rRNA.
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Affiliation(s)
- Alexandre Smirnov
- Department of Molecular and Cellular Genetics, UMR 7156, Centre National de Recherche Scientifique-Université Louis Pasteur,Strasbourg 67084, France
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41
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Geary C, Baudrey S, Jaeger L. Comprehensive features of natural and in vitro selected GNRA tetraloop-binding receptors. Nucleic Acids Res 2007; 36:1138-52. [PMID: 18158305 PMCID: PMC2275092 DOI: 10.1093/nar/gkm1048] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG … AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied ‘11nt’ GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC … GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA–RNA interactions are proposed.
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Affiliation(s)
- Cody Geary
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California at Santa Barbara, Santa Barbara, CA 93106-9510, USA
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42
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Zhong X, Tao X, Stombaugh J, Leontis N, Ding B. Tertiary structure and function of an RNA motif required for plant vascular entry to initiate systemic trafficking. EMBO J 2007; 26:3836-46. [PMID: 17660743 PMCID: PMC1952227 DOI: 10.1038/sj.emboj.7601812] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Accepted: 07/02/2007] [Indexed: 11/08/2022] Open
Abstract
Vascular entry is a decisive step for the initiation of long-distance movement of infectious and endogenous RNAs, silencing signals and developmental/defense signals in plants. However, the mechanisms remain poorly understood. We used Potato spindle tuber viroid (PSTVd) as a model to investigate the direct role of the RNA itself in vascular entry. We report here the identification of an RNA motif that is required for PSTVd to traffic from nonvascular into the vascular tissue phloem to initiate systemic infection. This motif consists of nucleotides U/C that form a water-inserted cis Watson-Crick/Watson-Crick base pair flanked by short helices that comprise canonical Watson-Crick/Watson-Crick base pairs. This tertiary structural model was inferred by comparison with X-ray crystal structures of similar motifs in rRNAs and is supported by combined mutagenesis and covariation analyses. Hydration pattern analysis suggests that water insertion induces a widened minor groove conducive to protein and/or RNA interactions. Our model and approaches have broad implications to investigate the RNA structural motifs in other RNAs for vascular entry and to study the basic principles of RNA structure-function relationships.
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Affiliation(s)
- Xuehua Zhong
- Department of Plant Cellular and Molecular Biology and Plant Biotechnology Center, Ohio State University, Columbus, OH, USA
| | - Xiaorong Tao
- Department of Plant Cellular and Molecular Biology and Plant Biotechnology Center, Ohio State University, Columbus, OH, USA
| | - Jesse Stombaugh
- Department of Chemistry and Center for Biomolecular Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - Neocles Leontis
- Department of Chemistry and Center for Biomolecular Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - Biao Ding
- Department of Plant Cellular and Molecular Biology and Plant Biotechnology Center, Ohio State University, Columbus, OH, USA
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43
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Vokacova Z, Sponer J, Sponer JE, Sychrovský V. Theoretical study of the scalar coupling constants across the noncovalent contacts in RNA base pairs: the cis- and trans-watson-crick/sugar edge base pair family. J Phys Chem B 2007; 111:10813-24. [PMID: 17713941 DOI: 10.1021/jp072822p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The structure and function of RNA molecules are substantially affected by non-Watson-Crick base pairs actively utilizing the 2'-hydroxyl group of ribose. Here we correlate scalar coupling constants across the noncovalent contacts calculated for the cis- and trans-WC/SE (Watson-Crick/sugar edge) RNA base pairs with the geometry of base to base and sugar to base hydrogen bond(s). 23 RNA base pairs from the 32 investigated were found in RNA crystal structures, and the calculated scalar couplings are therefore experimentally relevant with regard to the binding patterns occurring in this class of RNA base pairs. The intermolecular scalar couplings 1hJ(N,H), 2hJ(N,N), 2hJ(C,H), and 3hJ(C,N) were calculated for the N-H...N and N-H...O=C base to base contacts and various noncovalent links between the sugar hydroxyl and RNA base. Also, the intramolecular 1J(N,H) and 2J(C,H) couplings were calculated for the amino or imino group of RNA base and the ribose 2'-hydroxyl group involved in the noncovalent interactions. The calculated scalar couplings have implications for validation of local geometry, show specificity for the amino and imino groups of RNA base involved in the linkage, and can be used for discrimination between the cis- and trans-WC/SE base pairs. The RNA base pairs within an isosteric subclass of the WC/SE binding patterns can be further sorted according to the scalar couplings calculated across different local noncovalent contacts. The effect of explicit water inserted in the RNA base pairs on the magnitude of the scalar couplings was calculated, and the data for discrimination between the water-inserted and direct RNA base pairs are presented. The calculated NMR data are significant for structural interpretation of the scalar couplings in the noncanonical RNA base pairs.
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Affiliation(s)
- Zuzana Vokacova
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo Square 2, 166 10 Prague 6, Czech Republic
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44
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Sponer JE, Réblova K, Mokdad A, Sychrovský V, Leszczynski J, Sponer J. Leading RNA tertiary interactions: structures, energies, and water insertion of A-minor and P-interactions. A quantum chemical view. J Phys Chem B 2007; 111:9153-64. [PMID: 17602515 DOI: 10.1021/jp0704261] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Complex molecular shapes of ribosomal RNA molecules are stabilized by recurrent types of tertiary interactions involving highly specific and conserved non-Watson-Crick base pairs, triplets, and quartets. We analyzed the intrinsic structure and stability of the P-motif and the four basic types of A-minor interactions (types I, II, III, and 0), which represent the most prominent RNA tertiary interaction patterns refined in the course of evolution. In the studied interactions, the electron correlation component of the stabilization usually exceeds the Hartree-Fock (HF) term, leading to a strikingly different balance of forces as compared to standard base pairing stabilized primarily by the HF term. In other words, the A-minor and P-interactions are considerably more influenced by the dispersion energy as compared to canonical base pairs, which makes them particularly suitable to zip the folded RNA structures that are substantially hydrated even in their interior. Continuum solvent COSMO calculations confirm that the stability of the canonical GC base pair is affected (reduced) by the continuum solvent screening considerably more than the stability of the A-minor interaction. Among the studied systems, the strong A-minor II and weak A-minor III interactions require water molecules to stabilize the experimental geometry. Gas-phase optimization of the canonical A-minor II A/CG triplet without water results in a geometry that is clearly inconsistent with the RNA structure. The gas-phase structure of the P-interaction and the most stable A-minor I interaction nicely agrees with the geometries occurring in the ribosome. A-minor I can also adopt an alternative water-mediated substate rather often observed in X-ray and molecular dynamics studies. The A-minor I water bridge, however, does not appear to stabilize the tertiary contact, and its role is to provide structural flexibility to this binding pattern within the context of the RNA structure. Interestingly, the insertion of a polar water molecule in the A-minor I A/CG tertiary contact occurring in the A/C tertiary pair is stabilized primarily by the HF (electrostatic) interaction energy, while the dispersion-controlled A/G contact remains firmly bound. Thus, the intrinsic balance of forces as revealed by quantum mechanics (QM) calculations nicely correlates with many behavioral aspects of the studied interactions inside RNA. The comparison of interaction energies computed using quantum chemistry and an AMBER force field reveals that common molecular mechanics calculations perform rather well, except that the strength of the P-interaction is modestly overestimated. We also briefly discuss the non-negligible methodological differences when evaluating simple base-base nucleic acids base pairs and the complex RNA tertiary base pairing patterns using QM procedures.
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Affiliation(s)
- Judit E Sponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic.
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45
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McDowell SE, Špačková N, Šponer J, Walter NG. Molecular dynamics simulations of RNA: an in silico single molecule approach. Biopolymers 2007; 85:169-84. [PMID: 17080418 PMCID: PMC2018183 DOI: 10.1002/bip.20620] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RNA molecules are now known to be involved in the processing of genetic information at all levels, taking on a wide variety of central roles in the cell. Understanding how RNA molecules carry out their biological functions will require an understanding of structure and dynamics at the atomistic level, which can be significantly improved by combining computational simulation with experiment. This review provides a critical survey of the state of molecular dynamics (MD) simulations of RNA, including a discussion of important current limitations of the technique and examples of its successful application. Several types of simulations are discussed in detail, including those of structured RNA molecules and their interactions with the surrounding solvent and ions, catalytic RNAs, and RNA-small molecule and RNA-protein complexes. Increased cooperation between theorists and experimentalists will allow expanded judicious use of MD simulations to complement conceptually related single molecule experiments. Such cooperation will open the door to a fundamental understanding of the structure-function relationships in diverse and complex RNA molecules. .
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Affiliation(s)
- S. Elizabeth McDowell
- Biophysics Research Division, Single Molecule Analysis Group, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055
| | - Nad'a Špačková
- 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
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague
| | - Nils G. Walter
- Department of Chemistry, Single Molecule Analysis Group, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055
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46
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Gagnon MG, Mukhopadhyay A, Steinberg SV. Close Packing of Helices 3 and 12 of 16 S rRNA Is Required for the Normal Ribosome Function. J Biol Chem 2006; 281:39349-57. [PMID: 17060325 DOI: 10.1074/jbc.m607725200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The along-groove packing motif is a quasi-reciprocal arrangement of two RNA double helices in which a backbone of each helix is closely packed within the minor groove of the other helix. At the center of the inter-helix contact, a GU base pair in one helix packs against a Watson-Crick base pair in the other helix. Here, based on in vivo selection from a combinatorial gene library of 16 S rRNA and on functional characterization of the selected clones, we demonstrate that the normal ribosome performance requires that helices 3 and 12 be closely packed. In some clones the Watson-Crick and GU base pairs exchange in their positions between the two helices, which affects neither the quality of the helix packing, nor the ribosome function. On the other hand, perturbations in the close packing usually lead to a substantial drop in the ribosome activity. The functionality of the clones containing such perturbations may depend on the presence of particular elements in the vicinity of the area of contact between helices 3 and 12. Such cases do not exist in natural 16 S rRNA, and their selection enriches our knowledge of the constraints imposed on the structure of ribosomal RNA in functional ribosomes.
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Affiliation(s)
- Matthieu G Gagnon
- Département de Biochimie, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
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47
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McCrate NE, Varner ME, Kim KI, Nagan MC. Molecular dynamics simulations of human tRNA Lys,3 UUU: the role of modified bases in mRNA recognition. Nucleic Acids Res 2006; 34:5361-8. [PMID: 17012271 PMCID: PMC1636460 DOI: 10.1093/nar/gkl580] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Accuracy in translation of the genetic code into proteins depends upon correct tRNA–mRNA recognition in the context of the ribosome. In human tRNAUUULys,3 three modified bases are present in the anticodon stem–loop—2-methylthio-N6-threonylcarbamoyladenosine at position 37 (ms2t6A37), 5-methoxycarbonylmethyl-2-thiouridine at position 34 (mcm5s2U34) and pseudouridine (ψ) at position 39—two of which, ms2t6A37 and mcm5s2U34, are required to achieve wild-type binding activity of wild-type human tRNAUUULys,3 [C. Yarian, M. Marszalek, E. Sochacka, A. Malkiewicz, R. Guenther, A. Miskiewicz and P. F. Agris (2000) Biochemistry, 39, 13390–13395]. Molecular dynamics simulations of nine tRNA anticodon stem–loops with different combinations of nonstandard bases were performed. The wild-type simulation exhibited a canonical anticodon stair-stepped conformation. The ms2t6 modification at position 37 is required for maintenance of this structure and reduces solvent accessibility of U36. Ms2t6A37 generally hydrogen bonds across the loop and may prevent U36 from rotating into solution. A water molecule does coordinate to ψ39 most of the simulation time but weakly, as most of the residence lifetimes are <40 ps.
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Affiliation(s)
| | | | | | - Maria C. Nagan
- To whom correspondence should be addressed. Tel: +1 660 785 4084; Fax: +1 660 785 4045;
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