1
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Le Boulch M, Jacquet E, Nhiri N, Shmulevitz M, Jaïs PH. Rational design of an artificial tethered enzyme for non-templated post-transcriptional mRNA polyadenylation by the second generation of the C3P3 system. Sci Rep 2024; 14:5156. [PMID: 38431749 PMCID: PMC10908868 DOI: 10.1038/s41598-024-55947-0] [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: 10/22/2023] [Accepted: 02/29/2024] [Indexed: 03/05/2024] Open
Abstract
We have previously introduced the first generation of C3P3, an artificial system that allows the autonomous in-vivo production of mRNA with m7GpppN-cap. While C3P3-G1 synthesized much larger amounts of capped mRNA in human cells than conventional nuclear expression systems, it produced a proportionately much smaller amount of the corresponding proteins, indicating a clear defect of mRNA translatability. A possible mechanism for this poor translatability could be the rudimentary polyadenylation of the mRNA produced by the C3P3-G1 system. We therefore sought to develop the C3P3-G2 system using an artificial enzyme to post-transcriptionally lengthen the poly(A) tail. This system is based on the mutant mouse poly(A) polymerase alpha fused at its N terminus with an N peptide from the λ virus, which binds to BoxBr sequences placed in the 3'UTR region of the mRNA of interest. The resulting system selectively brings mPAPαm7 to the target mRNA to elongate its poly(A)-tail to a length of few hundred adenosine. Such elongation of the poly(A) tail leads to an increase in protein expression levels of about 2.5-3 times in cultured human cells compared to the C3P3-G1 system. Finally, the coding sequence of the tethered mutant poly(A) polymerase can be efficiently fused to that of the C3P3-G1 enzyme via an F2A sequence, thus constituting the single-ORF C3P3-G2 enzyme. These technical developments constitute an important milestone in improving the performance of the C3P3 system, paving the way for its applications in bioproduction and non-viral human gene therapy.
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Affiliation(s)
- Marine Le Boulch
- Eukarÿs SAS, Pépinière Genopole, 4 rue Pierre Fontaine, Genopole Entreprises Campus 3, 4 Rue Pierre Fontaine, 91000, Evry-Courcouronnes, France
| | - Eric Jacquet
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Saclay, Avenue de la Terrasse, 91198, Gif-Sur-Yvette, France
| | - Naïma Nhiri
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Saclay, Avenue de la Terrasse, 91198, Gif-Sur-Yvette, France
| | - Maya Shmulevitz
- Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, 6-142J Katz Group Centre for Pharmacy and Health Research, 114 Street NW, Edmonton, AB, T6G 2E1, Canada
| | - Philippe H Jaïs
- Eukarÿs SAS, Pépinière Genopole, 4 rue Pierre Fontaine, Genopole Entreprises Campus 3, 4 Rue Pierre Fontaine, 91000, Evry-Courcouronnes, France.
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2
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Vila-Sanjurjo A, Mallo N, Elson JL, Smith PM, Blakely EL, Taylor RW. Structural analysis of mitochondrial rRNA gene variants identified in patients with deafness. Front Physiol 2023; 14:1163496. [PMID: 37362424 PMCID: PMC10285412 DOI: 10.3389/fphys.2023.1163496] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/18/2023] [Indexed: 06/28/2023] Open
Abstract
The last few years have witnessed dramatic advances in our understanding of the structure and function of the mammalian mito-ribosome. At the same time, the first attempts to elucidate the effects of mito-ribosomal fidelity (decoding accuracy) in disease have been made. Hence, the time is right to push an important frontier in our understanding of mitochondrial genetics, that is, the elucidation of the phenotypic effects of mtDNA variants affecting the functioning of the mito-ribosome. Here, we have assessed the structural and functional role of 93 mitochondrial (mt-) rRNA variants thought to be associated with deafness, including those located at non-conserved positions. Our analysis has used the structural description of the human mito-ribosome of the highest quality currently available, together with a new understanding of the phenotypic manifestation of mito-ribosomal-associated variants. Basically, any base change capable of inducing a fidelity phenotype may be considered non-silent. Under this light, out of 92 previously reported mt-rRNA variants thought to be associated with deafness, we found that 49 were potentially non-silent. We also dismissed a large number of reportedly pathogenic mtDNA variants, 41, as polymorphisms. These results drastically update our view on the implication of the primary sequence of mt-rRNA in the etiology of deafness and mitochondrial disease in general. Our data sheds much-needed light on the question of how mt-rRNA variants located at non-conserved positions may lead to mitochondrial disease and, most notably, provide evidence of the effect of haplotype context in the manifestation of some mt-rRNA variants.
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Affiliation(s)
- Antón Vila-Sanjurjo
- Grupo GIBE. Departamento de Bioloxía e Centro Interdisciplinar de Química e Bioloxía (CICA), Universidade da Coruña (UDC), A Coruña, Spain
| | - Natalia Mallo
- Grupo GIBE. Departamento de Bioloxía e Centro Interdisciplinar de Química e Bioloxía (CICA), Universidade da Coruña (UDC), A Coruña, Spain
| | - Joanna L. Elson
- The Bioscience Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Paul M. Smith
- Department of Paediatrics, Raigmore Hospital, Inverness, United Kingdom
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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3
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Shin JH, Bonilla SL, Denny SK, Greenleaf WJ, Herschlag D. Dissecting the energetic architecture within an RNA tertiary structural motif via high-throughput thermodynamic measurements. Proc Natl Acad Sci U S A 2023; 120:e2220485120. [PMID: 36897989 PMCID: PMC10243134 DOI: 10.1073/pnas.2220485120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/01/2023] [Indexed: 03/12/2023] Open
Abstract
Structured RNAs and RNA/protein complexes perform critical cellular functions. They often contain structurally conserved tertiary contact "motifs," whose occurrence simplifies the RNA folding landscape. Prior studies have focused on the conformational and energetic modularity of intact motifs. Here, we turn to the dissection of one common motif, the 11nt receptor (11ntR), using quantitative analysis of RNA on a massively parallel array to measure the binding of all single and double 11ntR mutants to GAAA and GUAA tetraloops, thereby probing the energetic architecture of the motif. While the 11ntR behaves as a motif, its cooperativity is not absolute. Instead, we uncovered a gradient from high cooperativity amongst base-paired and neighboring residues to additivity between distant residues. As expected, substitutions at residues in direct contact with the GAAA tetraloop resulted in the largest decreases to binding, and energetic penalties of mutations were substantially smaller for binding to the alternate GUAA tetraloop, which lacks tertiary contacts present with the canonical GAAA tetraloop. However, we found that the energetic consequences of base partner substitutions are not, in general, simply described by base pair type or isostericity. We also found exceptions to the previously established stability-abundance relationship for 11ntR sequence variants. These findings of "exceptions to the rule" highlight the power of systematic high-throughput approaches to uncover novel variants for future study in addition to providing an energetic map of a functional RNA.
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Affiliation(s)
- John H. Shin
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
| | - Steve L. Bonilla
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO80045
| | - Sarah K. Denny
- Department of Genetics, Stanford University School of Medicine, Stanford, CA94305
- Scribe Therapeutics, Alameda, CA94501
| | - William J. Greenleaf
- Department of Genetics, Stanford University School of Medicine, Stanford, CA94305
- Department of Applied Physics, Stanford University, Stanford, CA94305
- Chan Zuckerberg Biohub, San Francisco, CA94158
| | - Daniel Herschlag
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- ChEM-H Institute, Stanford University, Stanford, CA94305
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4
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Saon MS, Kirkpatrick CC, Znosko BM. Identification and characterization of RNA pentaloop sequence families. NAR Genom Bioinform 2023; 5:lqac102. [PMID: 36632613 PMCID: PMC9830547 DOI: 10.1093/nargab/lqac102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/28/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
One of the current methods for predicting RNA tertiary structure is fragment-based homology, which predicts tertiary structure from secondary structure. For a successful prediction, this method requires a library of the tertiary structures of small motifs clipped from previously solved RNA 3D structures. Because of the limited number of available tertiary structures, it is not practical to find structures for all sequences of all motifs. Identifying sequence families for motifs can fill the gaps because all sequences within a family are expected to have similar structural features. Currently, a collection of well-characterized sequence families has been identified for tetraloops. Because of their prevalence and biological functions, pentaloop structures should also be well-characterized. In this study, 10 pentaloop sequence families are identified. For each family, the common and distinguishing structural features are highlighted. These sequence families can be used to predict the tertiary structure of pentaloop sequences for which a solved structure is not available.
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Affiliation(s)
- Md Sharear Saon
- Department of Chemistry, Saint Louis University, Saint Louis, MO 63103, USA
| | | | - Brent M Znosko
- To whom correspondence should be addressed. Tel: +1 314 977 8567; Fax: +1 314 977 2521;
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5
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Zuber J, Schroeder SJ, Sun H, Turner DH, Mathews DH. Nearest neighbor rules for RNA helix folding thermodynamics: improved end effects. Nucleic Acids Res 2022; 50:5251-5262. [PMID: 35524574 PMCID: PMC9122537 DOI: 10.1093/nar/gkac261] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/29/2022] [Accepted: 04/08/2022] [Indexed: 12/26/2022] Open
Abstract
Nearest neighbor parameters for estimating the folding stability of RNA secondary structures are in widespread use. For helices, current parameters penalize terminal AU base pairs relative to terminal GC base pairs. We curated an expanded database of helix stabilities determined by optical melting experiments. Analysis of the updated database shows that terminal penalties depend on the sequence identity of the adjacent penultimate base pair. New nearest neighbor parameters that include this additional sequence dependence accurately predict the measured values of 271 helices in an updated database with a correlation coefficient of 0.982. This refined understanding of helix ends facilitates fitting terms for base pair stacks with GU pairs. Prior parameter sets treated 5′GGUC3′ paired to 3′CUGG5′ separately from other 5′GU3′/3′UG5′ stacks. The improved understanding of helix end stability, however, makes the separate treatment unnecessary. Introduction of the additional terms was tested with three optical melting experiments. The average absolute difference between measured and predicted free energy changes at 37°C for these three duplexes containing terminal adjacent AU and GU pairs improved from 1.38 to 0.27 kcal/mol. This confirms the need for the additional sequence dependence in the model.
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Affiliation(s)
- Jeffrey Zuber
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Susan J Schroeder
- Department of Chemistry and Biochemistry, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Hongying Sun
- Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Douglas H Turner
- Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.,Department of Chemistry, University of Rochester, Rochester, NY 14627, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.,Department of Biostatistics & Computational Biology, University of Rochester, Rochester, NY 14642, USA
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6
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Khisamutdinov EF, Sweeney BA, Leontis NB. Context-sensitivity of isosteric substitutions of non-Watson-Crick basepairs in recurrent RNA 3D motifs. Nucleic Acids Res 2021; 49:9574-9593. [PMID: 34403481 PMCID: PMC8450098 DOI: 10.1093/nar/gkab703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 07/29/2021] [Indexed: 02/01/2023] Open
Abstract
Sequence variation in a widespread, recurrent, structured RNA 3D motif, the Sarcin/Ricin (S/R), was studied to address three related questions: First, how do the stabilities of structured RNA 3D motifs, composed of non-Watson–Crick (non-WC) basepairs, compare to WC-paired helices of similar length and sequence? Second, what are the effects on the stabilities of such motifs of isosteric and non-isosteric base substitutions in the non-WC pairs? And third, is there selection for particular base combinations in non-WC basepairs, depending on the temperature regime to which an organism adapts? A survey of large and small subunit rRNAs from organisms adapted to different temperatures revealed the presence of systematic sequence variations at many non-WC paired sites of S/R motifs. UV melting analysis and enzymatic digestion assays of oligonucleotides containing the motif suggest that more stable motifs tend to be more rigid. We further found that the base substitutions at non-Watson–Crick pairing sites can significantly affect the thermodynamic stabilities of S/R motifs and these effects are highly context specific indicating the importance of base-stacking and base-phosphate interactions on motif stability. This study highlights the significance of non-canonical base pairs and their contributions to modulating the stability and flexibility of RNA molecules.
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Affiliation(s)
- Emil F Khisamutdinov
- Department of Chemistry and Center for Photochemical Science, Bowling Green State University, Bowling Green, OH 43403, USA.,Department of Chemistry, Ball State University, Muncie, IN 47306, USA
| | - Blake A Sweeney
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.,European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, UK
| | - Neocles B Leontis
- Department of Chemistry and Center for Photochemical Science, Bowling Green State University, Bowling Green, OH 43403, USA
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7
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Tang Z, Akhter S, Ramprasad A, Wang X, Reibarkh M, Wang J, Aryal S, Thota SS, Zhao J, Douglas JT, Gao P, Holmstrom ED, Miao Y, Wang J. Recognition of single-stranded nucleic acids by small-molecule splicing modulators. Nucleic Acids Res 2021; 49:7870-7883. [PMID: 34283224 PMCID: PMC8373063 DOI: 10.1093/nar/gkab602] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/24/2021] [Accepted: 07/01/2021] [Indexed: 12/16/2022] Open
Abstract
Risdiplam is the first approved small-molecule splicing modulator for the treatment of spinal muscular atrophy (SMA). Previous studies demonstrated that risdiplam analogues have two separate binding sites in exon 7 of the SMN2 pre-mRNA: (i) the 5'-splice site and (ii) an upstream purine (GA)-rich binding site. Importantly, the sequence of this GA-rich binding site significantly enhanced the potency of risdiplam analogues. In this report, we unambiguously determined that a known risdiplam analogue, SMN-C2, binds to single-stranded GA-rich RNA in a sequence-specific manner. The minimum required binding sequence for SMN-C2 was identified as GAAGGAAGG. We performed all-atom simulations using a robust Gaussian accelerated molecular dynamics (GaMD) method, which captured spontaneous binding of a risdiplam analogue to the target nucleic acids. We uncovered, for the first time, a ligand-binding pocket formed by two sequential GAAG loop-like structures. The simulation findings were highly consistent with experimental data obtained from saturation transfer difference (STD) NMR and structure-affinity-relationship studies of the risdiplam analogues. Together, these studies illuminate us to understand the molecular basis of single-stranded purine-rich RNA recognition by small-molecule splicing modulators with an unprecedented binding mode.
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Affiliation(s)
- Zhichao Tang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Sana Akhter
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66047, USA
| | - Ankita Ramprasad
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Xiao Wang
- Analytical Research & Development, Merck and Co., Inc., Kenilworth, NJ 07033, USA
| | - Mikhail Reibarkh
- Analytical Research & Development, Merck and Co., Inc., Kenilworth, NJ 07033, USA
| | - Jinan Wang
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66047, USA
| | - Sadikshya Aryal
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Srinivas S Thota
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Junxing Zhao
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Justin T Douglas
- Nuclear Magnetic Resonance Lab, University of Kansas, Lawrence, KS 66045, USA
| | - Philip Gao
- Protein Production Group, University of Kansas, Lawrence, KS 66047, USA
| | - Erik D Holmstrom
- Department of Molecular Biosciences and Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA
| | - Yinglong Miao
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66047, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA
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8
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Redman RL, Krauss IJ. Directed Evolution of 2'-Fluoro-Modified, RNA-Supported Carbohydrate Clusters That Bind Tightly to HIV Antibody 2G12. J Am Chem Soc 2021; 143:8565-8571. [PMID: 34096703 DOI: 10.1021/jacs.1c03194] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Carbohydrate binding proteins (CBPs) are attractive targets in medicine and biology. Multivalency, with several glycans binding to several binding pockets in the CBP, is important for high-affinity interactions. Herein, we describe a novel platform for design of multivalent carbohydrate cluster ligands by directed evolution, in which serum-stable 2'-fluoro modified RNA (F-RNA) backbones evolve to present the glycan in optimal clusters. We have validated this method by the selection of oligomannose (Man9) glycan clusters from a sequence pool of ∼1013 that bind to broadly neutralizing HIV antibody 2G12 with 13 to 36 nM affinities.
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Affiliation(s)
- Richard L Redman
- Department of Chemistry, Brandeis University, 415 South Street MS 015, Waltham, Massachusetts 02454, United States
| | - Isaac J Krauss
- Department of Chemistry, Brandeis University, 415 South Street MS 015, Waltham, Massachusetts 02454, United States
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9
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Richardson KE, Kirkpatrick CC, Znosko BM. RNA CoSSMos 2.0: an improved searchable database of secondary structure motifs in RNA three-dimensional structures. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2020; 2020:5707338. [PMID: 31950189 PMCID: PMC6966092 DOI: 10.1093/database/baz153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 11/12/2019] [Accepted: 12/13/2019] [Indexed: 01/29/2023]
Abstract
The RNA Characterization of Secondary Structure Motifs, RNA CoSSMos, database is a freely accessible online database that allows users to identify secondary structure motifs among RNA 3D structures and explore their structural features. RNA CoSSMos 2.0 now requires two closing base pairs for all RNA loop motifs to create a less redundant database of secondary structures. Furthermore, RNA CoSSMos 2.0 represents an upgraded database with new features that summarize search findings and aid in the search for 3D structural patterns among RNA secondary structure motifs. Previously, users were limited to viewing search results individually, with no built-in tools to compare search results. RNA CoSSMos 2.0 provides two new features, allowing users to summarize, analyze and compare their search result findings. A function has been added to the website that calculates the average and representative structures of the search results. Additionally, users can now view a summary page of their search results that reports percentages of each structural feature found, including sugar pucker, glycosidic linkage, hydrogen bonding patterns and stacking interactions. Other upgrades include a newly embedded NGL structural viewer, the option to download the clipped structure coordinates in *.pdb format and improved NMR structure results. RNA CoSSMos 2.0 is no longer simply a search engine for a structure database; it now has the capability of analyzing, comparing and summarizing search results. Database URL: http://rnacossmos.com
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Affiliation(s)
- Katherine E Richardson
- Saint Louis University, Department of Chemistry, 3501 Laclede Avenue, St. Louis, MO 63103 USA
| | - Charles C Kirkpatrick
- Saint Louis University, Department of Chemistry, 3501 Laclede Avenue, St. Louis, MO 63103 USA
| | - Brent M Znosko
- Saint Louis University, Department of Chemistry, 3501 Laclede Avenue, St. Louis, MO 63103 USA
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10
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Widner DL, Harris KA, Corey L, Breaker RR. Bacillus halodurans OapB forms a high-affinity complex with the P13 region of the noncoding RNA OLE. J Biol Chem 2020; 295:9326-9334. [PMID: 32376692 DOI: 10.1074/jbc.ra120.012676] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/28/2020] [Indexed: 11/06/2022] Open
Abstract
Noncoding RNAs (ncRNAs) longer than 200 nucleotides are rare in bacteria, likely because bacterial genomes are under strong evolutionary pressures to maintain a small genome size. Of the long ncRNAs unique to bacteria, the OLE (ornate, large, extremophilic) RNA class is among the largest and most structurally complex. OLE RNAs form a ribonucleoprotein (RNP) complex by partnering with at least two proteins, OapA and OapB, that directly bind OLE RNA. The biochemical functions of the OLE RNP complex remain unknown, but are required for proper adaptation to certain environmental stresses, such as cold temperatures, short chain alcohols, and high magnesium concentrations. In the current study, we used electrophoretic mobility shift assays to examine the binding of OLE RNA fragments by OapB and found that OapB recognizes a small subregion of OLE RNA, including stem P13, with a dissociation constant (KD ) of ∼700 pm Analyses with mutated RNA constructs, and the application of in vitro selection, revealed that strong binding of OLE RNA by OapB requires a stem containing a precisely located single-nucleotide bulge and a GNRA tetraloop. Although the vast majority of bacteria with the ole gene also have the oapB gene, there are many whose genomes contain oapB but lack ole, suggesting that OapB has other RNA partners in some species that might exhibit similar structural features.
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Affiliation(s)
- Danielle L Widner
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Kimberly A Harris
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, USA.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Lukas Corey
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Ronald R Breaker
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, Connecticut, USA .,Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, USA.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
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11
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Richardson KE, Adams MS, Kirkpatrick CC, Gohara DW, Znosko BM. Identification and Characterization of New RNA Tetraloop Sequence Families. Biochemistry 2019; 58:4809-4820. [PMID: 31714066 DOI: 10.1021/acs.biochem.9b00535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
There is an abundance of RNA sequence information available due to the efforts of sequencing projects. However, current techniques implemented to solve the tertiary structures of RNA, such as NMR and X-ray crystallography, are difficult and time-consuming. Therefore, biophysical techniques are not able to keep pace with the abundance of sequence information available. Because of this, there is a need to develop quick and efficient ways to predict RNA tertiary structure from sequence. One promising approach is to identify structural patterns within previously solved 3D structures and apply these patterns to new sequences. RNA tetraloops are one of the most common naturally occurring secondary structure motifs. Here, we use RNA Characterization of Secondary Structure Motifs (CoSSMos), Dissecting the Spatial Structure of RNA (DSSR), and a bioinformatic approach to search for and characterize tertiary structure patterns among tetraloops. Not surprising, we identified the well-known GNRA and UNCG tetraloops, as well as the previously identified RNYA tetraloop. However, some previously identified characteristics of these families were not observed in this data set, and some new characteristics were identified. In addition, we also identified and characterized three new tetraloop sequence families: YGAR, UGGU, and RMSA. This new structural information sheds light on the tertiary structure of tetraloops and contributes to the efforts of RNA tertiary structure prediction from sequence.
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Affiliation(s)
- Katherine E Richardson
- Department of Chemistry , Saint Louis University , Saint Louis , Missouri 63103 , United States
| | - Miranda S Adams
- Department of Chemistry , Saint Louis University , Saint Louis , Missouri 63103 , United States
| | - Charles C Kirkpatrick
- Department of Chemistry , Saint Louis University , Saint Louis , Missouri 63103 , United States
| | - David W Gohara
- Department of Biochemistry and Molecular Biology , Saint Louis University , Saint Louis , Missouri 63103 , United States
| | - Brent M Znosko
- Department of Chemistry , Saint Louis University , Saint Louis , Missouri 63103 , United States
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12
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Koirala D, Shao Y, Koldobskaya Y, Fuller JR, Watkins AM, Shelke SA, Pilipenko EV, Das R, Rice PA, Piccirilli JA. A conserved RNA structural motif for organizing topology within picornaviral internal ribosome entry sites. Nat Commun 2019; 10:3629. [PMID: 31399592 PMCID: PMC6689051 DOI: 10.1038/s41467-019-11585-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 07/09/2019] [Indexed: 12/30/2022] Open
Abstract
Picornaviral IRES elements are essential for initiating the cap-independent viral translation. However, three-dimensional structures of these elements remain elusive. Here, we report a 2.84-Å resolution crystal structure of hepatitis A virus IRES domain V (dV) in complex with a synthetic antibody fragment-a crystallization chaperone. The RNA adopts a three-way junction structure, topologically organized by an adenine-rich stem-loop motif. Despite no obvious sequence homology, the dV architecture shows a striking similarity to a circularly permuted form of encephalomyocarditis virus J-K domain, suggesting a conserved strategy for organizing the domain architecture. Recurrence of the motif led us to use homology modeling tools to compute a 3-dimensional structure of the corresponding domain of foot-and-mouth disease virus, revealing an analogous domain organizing motif. The topological conservation observed among these IRESs and other viral domains implicates a structured three-way junction as an architectural scaffold to pre-organize helical domains for recruiting the translation initiation machinery.
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Affiliation(s)
- Deepak Koirala
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Yaming Shao
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Yelena Koldobskaya
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - James R Fuller
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Andrew M Watkins
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Sandip A Shelke
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Evgeny V Pilipenko
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Rhiju Das
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Joseph A Piccirilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA. .,Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA.
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13
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Birman Y, Khorsand S, Tu E, Mortensen RB, Butko MT. Second-harmonic generation-based methods to detect and characterize ligand-induced RNA conformational changes. Methods 2019; 167:92-104. [PMID: 31116965 DOI: 10.1016/j.ymeth.2019.05.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/11/2019] [Accepted: 05/15/2019] [Indexed: 10/26/2022] Open
Abstract
Second-harmonic generation (SHG) is a biophysical tool that senses ligand-induced conformational changes in biomolecules. The Biodesy Delta™ has been developed as a high-throughput screening platform to monitor conformational changes in proteins and oligonucleotides by SHG to support drug discovery efforts. This work will outline (1) an overview of this technology, (2) detailed protocols for optimizing screening-ready SHG assays on RNA targets, (3) practical considerations for developing robust and informative SHG measurements, and (4) a case study that demonstrates the application of these recommendations on an RNA target. The previously published theophylline aptamer SHG assay [1] was further optimized to maximize the assay window between the positive control (theophylline) and the negative control (caffeine). Optimization of this assay provides practical considerations for building a robust SHG assay on an RNA target, including testing for specific tethering of the conjugate to the surface as well as testing tool compound response stability, reversibility, and concentration-dependence/affinity. A more robust, better-performing theophylline aptamer SHG assay was achieved that would be more appropriate for conducting a screen.
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Affiliation(s)
- Yuliya Birman
- Biodesy, Inc., South San Francisco 94080, United States
| | - Sina Khorsand
- Biodesy, Inc., South San Francisco 94080, United States
| | - Erick Tu
- Biodesy, Inc., South San Francisco 94080, United States
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14
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Singh A, Batra JK. Insight into the functional role of unique determinants in RNA component of RNase P of Mycobacterium tuberculosis. Int J Biol Macromol 2018; 119:937-944. [PMID: 30086331 DOI: 10.1016/j.ijbiomac.2018.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/03/2018] [Accepted: 08/04/2018] [Indexed: 10/28/2022]
Abstract
RNase P, an essential ribonucleoprotein enzyme is involved in processing 5' end of pre-tRNA molecules. All bacterial RNase P holoenzymes, including that of Mycobacterim tuberculosis, an important human pathogen contain a catalytically active RNA subunit and a protein subunit. However, the mycobacterial RNA is larger than typical bacterial RNase P RNAs. It contains the essential core structure and many unique features in the peripheral elements. In the current study, an extensive mutational analysis was performed to analyze the function of the unique features in P12, P15.A, P18 and P19 helices in the mycobacterial RNase P RNA. The study demonstrates that P12 interacts with monovalent and divalent ions and is important for the function of mycobacterial holoenzyme. The helices, P15.A and P18 appear to interact with ammonium and magnesium ions, respectively. P19 is involved in the thermostability of the RNA component as well as interaction with ammonium ions. A homology model of M. tuberculosis RNase P RNA indicates many new inter- and intra-helical interactions. The significance of the unique interactions paves way towards understanding the differential functioning of M. tuberculosis RNase P RNA, for exploring specific inhibition of the same in the pathogen to contain infection.
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Affiliation(s)
- Alla Singh
- Immunochemistry Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Janendra K Batra
- Immunochemistry Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India; Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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15
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Carr CE, Marky LA. Effect of GCAA stabilizing loops on three- and four-way intramolecular junctions. Phys Chem Chem Phys 2018; 20:5046-5056. [PMID: 29388988 DOI: 10.1039/c7cp08329g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tetraloops are a common way of changing the melting behavior of a DNA or RNA structure without changing the sequence of the stem. Because of the ubiquitous nature of tetraloops, our goal is to understand the effect a GCAA tetraloop, which belongs to the GNRA family of tetraloops, has on the unfolding thermodynamics of intramolecular junctions. Specifically, we have described the melting behavior of intramolecular three-way and four-way junctions where a T5 loop has been replaced with a GCAA tetraloops in different positions. Their thermodynamic profiles, including ΔnNa+ and ΔnW, were analyzed based on the position of the tetraloop. We obtained between -16.7 and -27.5 kcal mol-1 for all junctions studied. The experimental data indicates the influence of the GCAA tetraloop is primarily dictated by the native unfolding of the junction; if the tetraloop is placed on a stem that unfolds as a single domain when the tetraloop is not present, it will unfold as a single domain when the tetraloop is present but with a higher thermal stability. Conversely, if the tetraloop is placed on a stem which unfolds cooperatively with other stems when the tetraloop is not present, the tetraloop will increase the thermal stability of all the stems in the melting domain. The oligonucleotide structure and not the tetraloop itself affects ion uptake; three-way junctions do not gain an increase in ion uptake, but four-way junctions do. This is not the case for water immobilization, where the position of the tetraloop dictates the amount of water immobilized.
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Affiliation(s)
- Carolyn E Carr
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA.
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16
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Lee HT, Carr CE, Khutsishvili I, Marky LA. Effect of Loop Length and Sequence on the Stability of DNA Pyrimidine Triplexes with TAT Base Triplets. J Phys Chem B 2017; 121:9175-9184. [PMID: 28875701 DOI: 10.1021/acs.jpcb.7b07591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We report the thermodynamic contributions of loop length and loop sequence to the overall stability of DNA intramolecular pyrimidine triplexes. Two sets of triplexes were designed: in the first set, the C5 loop closing the triplex stem was replaced with 5'-CTnC loops (n = 1-5), whereas in the second set, both the duplex and triplex loops were replaced with a 5'-GCAA or 5'-AACG tetraloop. For the triplexes with a 5'-CTnC loop, the triplex with five bases in the loop has the highest stability relative to the control. A loop length lower than five compromises the strength of the base-pair stacks without decreasing the thermal stability, leading to a decreased enthalpy, whereas an increase in the loop length leads to a decreased enthalpy and a higher entropic penalty. The incorporation of the GCAA loop yielded more stable triplexes, whereas the incorporation of AACG in the triplex loop yielded a less stable triplex due to an unfavorable enthalpy term. Thus, addition of the GCAA tetraloop can cause an increase in the thermodynamics of the triplex without affecting the sequence or melting behavior and may result in an additional layer of genetic regulation.
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Affiliation(s)
- Hui-Ting Lee
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Carolyn E Carr
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Irine Khutsishvili
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Luis A Marky
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
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17
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Mapping the Universe of RNA Tetraloop Folds. Biophys J 2017; 113:257-267. [PMID: 28673616 DOI: 10.1016/j.bpj.2017.06.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 06/08/2017] [Accepted: 06/08/2017] [Indexed: 11/22/2022] Open
Abstract
We report a map of RNA tetraloop conformations constructed by calculating pairwise distances among all experimentally determined four-nucleotide hairpin loops. Tetraloops with similar structures are clustered together and, as expected, the two largest clusters are the canonical GNRA and UNCG folds. We identify clusters corresponding to known tetraloop folds such as GGUG, RNYA, AGNN, and CUUG. These clusters are represented in a simple two-dimensional projection that recapitulates the relationship among the different folds. The cluster analysis also identifies 20 novel tetraloop folds that are peculiar to specific positions in ribosomal RNAs and that are stabilized by tertiary interactions. In our RNA tetraloop database we find a significant number of non-GNRA and non-UNCG sequences adopting the canonical GNRA and UNCG folds. Conversely, we find a significant number of GNRA and UNCG sequences adopting non-GNRA and non-UNCG folds. Our analysis demonstrates that there is not a simple one-to-one, but rather a many-to-many mapping between tetraloop sequence and tetraloop fold.
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18
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Jedrzejczyk D, Gendaszewska-Darmach E, Pawlowska R, Chworos A. Designing synthetic RNA for delivery by nanoparticles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:123001. [PMID: 28004640 DOI: 10.1088/1361-648x/aa5561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The rapid development of synthetic biology and nanobiotechnology has led to the construction of various synthetic RNA nanoparticles of different functionalities and potential applications. As they occur naturally, nucleic acids are an attractive construction material for biocompatible nanoscaffold and nanomachine design. In this review, we provide an overview of the types of RNA and nucleic acid's nanoparticle design, with the focus on relevant nanostructures utilized for gene-expression regulation in cellular models. Structural analysis and modeling is addressed along with the tools available for RNA structural prediction. The functionalization of RNA-based nanoparticles leading to prospective applications of such constructs in potential therapies is shown. The route from the nanoparticle design and modeling through synthesis and functionalization to cellular application is also described. For a better understanding of the fate of targeted RNA after delivery, an overview of RNA processing inside the cell is also provided.
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Affiliation(s)
- Dominika Jedrzejczyk
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
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19
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Zgarbová M, Jurečka P, Banáš P, Havrila M, Šponer J, Otyepka M. Noncanonical α/γ Backbone Conformations in RNA and the Accuracy of Their Description by the AMBER Force Field. J Phys Chem B 2017; 121:2420-2433. [PMID: 28290207 DOI: 10.1021/acs.jpcb.7b00262] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The sugar-phosphate backbone of RNA can exist in diverse rotameric substates, giving RNA molecules enormous conformational variability. The most frequent noncanonical backbone conformation in RNA is α/γ = t/t, which is derived from the canonical backbone by a crankshaft motion and largely preserves the standard geometry of the RNA duplex. A similar conformation also exists in DNA, where it has been extensively studied and shown to be involved in DNA-protein interactions. However, the function of the α/γ = t/t conformation in RNA is poorly understood. Here, we present molecular dynamics simulations of several prototypical RNA structures obtained from X-ray and NMR experiments, including canonical and mismatched RNA duplexes, UUCG and GAGA tetraloops, Loop E, the sarcin-ricin loop, a parallel guanine quadruplex, and a viral pseudoknot. The stability of various noncanonical α/γ backbone conformations was analyzed with two AMBER force fields, ff99bsc0χOL3 and ff99bsc0χOL3 with the recent εζOL1 and βOL1 corrections for DNA. Although some α/γ substates were stable with seemingly well-described equilibria, many were unstable in our simulations. Notably, the most frequent noncanonical conformer α/γ = t/t was unstable in both tested force fields. Possible reasons for this instability are discussed. Our work reveals a potentially important artifact in RNA force fields and highlights a need for further force field refinement.
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Affiliation(s)
- Marie Zgarbová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Marek Havrila
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Jiří Šponer
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic.,Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University , 17. listopadu 12, 77146 Olomouc, Czech Republic
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20
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D'Ascenzo L, Leonarski F, Vicens Q, Auffinger P. Revisiting GNRA and UNCG folds: U-turns versus Z-turns in RNA hairpin loops. RNA (NEW YORK, N.Y.) 2017; 23:259-269. [PMID: 27999116 PMCID: PMC5311481 DOI: 10.1261/rna.059097.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/29/2016] [Indexed: 06/06/2023]
Abstract
When thinking about RNA three-dimensional structures, coming across GNRA and UNCG tetraloops is perceived as a boon since their folds have been extensively described. Nevertheless, analyzing loop conformations within RNA and RNP structures led us to uncover several instances of GNRA and UNCG loops that do not fold as expected. We noticed that when a GNRA does not assume its "natural" fold, it adopts the one we typically associate with a UNCG sequence. The same folding interconversion may occur for loops with UNCG sequences, for instance within tRNA anticodon loops. Hence, we show that some structured tetranucleotide sequences starting with G or U can adopt either of these folds. The underlying structural basis that defines these two fold types is the mutually exclusive stacking of a backbone oxygen on either the first (in GNRA) or the last nucleobase (in UNCG), generating an oxygen-π contact. We thereby propose to refrain from using sequences to distinguish between loop conformations. Instead, we suggest using descriptors such as U-turn (for "GNRA-type" folds) and a newly described Z-turn (for "UNCG-type" folds). Because tetraloops adopt for the largest part only two (inter)convertible turns, we are better able to interpret from a structural perspective loop interchangeability occurring in ribosomes and viral RNA. In this respect, we propose a general view on the inclination for a given sequence to adopt (or not) a specific fold. We also suggest how long-noncoding RNAs may adopt discrete but transient structures, which are therefore hard to predict.
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Affiliation(s)
- Luigi D'Ascenzo
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Filip Leonarski
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
| | - Quentin Vicens
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Pascal Auffinger
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
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21
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Haldar S, Kührová P, Banáš P, Spiwok V, Šponer J, Hobza P, Otyepka M. Insights into Stability and Folding of GNRA and UNCG Tetraloops Revealed by Microsecond Molecular Dynamics and Well-Tempered Metadynamics. J Chem Theory Comput 2016; 11:3866-77. [PMID: 26574468 DOI: 10.1021/acs.jctc.5b00010] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
RNA hairpins capped by 5'-GNRA-3' or 5'-UNCG-3' tetraloops (TLs) are prominent RNA structural motifs. Despite their small size, a wealth of experimental data, and recent progress in theoretical simulations of their structural dynamics and folding, our understanding of the folding and unfolding processes of these small RNA elements is still limited. Theoretical description of the folding and unfolding processes requires robust sampling, which can be achieved by either an exhaustive time scale in standard molecular dynamics simulations or sophisticated enhanced sampling methods, using temperature acceleration or biasing potentials. Here, we study structural dynamics of 5'-GNRA-3' and 5'-UNCG-3' TLs by 15-μs-long standard simulations and a series of well-tempered metadynamics, attempting to accelerate sampling by bias in a few chosen collective variables (CVs). Both methods provide useful insights. The unfolding and refolding mechanisms of the GNRA TL observed by well-tempered metadynamics agree with the (reverse) folding mechanism suggested by recent replica exchange molecular dynamics simulations. The orientation of the glycosidic bond of the GL4 nucleobase is critical for the UUCG TL folding pathway, and our data strongly support the hypothesis that GL4-anti forms a kinetic trap along the folding pathway. Along with giving useful insight, our study also demonstrates that using only a few CVs apparently does not capture the full folding landscape of the RNA TLs. Despite using several sophisticated selections of the CVs, formation of the loop appears to remain a hidden variable, preventing a full convergence of the metadynamics. Finally, our data suggest that the unfolded state might be overstabilized by the force fields used.
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Affiliation(s)
- Susanta Haldar
- Institute of Organic Chemistry and Biochemistry and Gilead Science Research Center, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.,Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague , Albertov 6, 128 43 Prague 2, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc , tř. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc , tř. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Vojtěch Spiwok
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague , Technická 3, 166 28 Prague 6, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Pavel Hobza
- Institute of Organic Chemistry and Biochemistry and Gilead Science Research Center, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc , tř. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc , tř. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
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22
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Imai S, Kumar P, Hellen CUT, D'Souza VM, Wagner G. An accurately preorganized IRES RNA structure enables eIF4G capture for initiation of viral translation. Nat Struct Mol Biol 2016; 23:859-64. [PMID: 27525590 DOI: 10.1038/nsmb.3280] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 07/21/2016] [Indexed: 02/06/2023]
Abstract
Many viruses bypass canonical cap-dependent translation in host cells by using internal ribosomal entry sites (IRESs) in their transcripts; IRESs hijack initiation factors for the assembly of initiation complexes. However, it is currently unknown how IRES RNAs recognize initiation factors that have no endogenous RNA binding partners; in a prominent example, the IRES of encephalomyocarditis virus (EMCV) interacts with the HEAT-1 domain of eukaryotic initiation factor 4G (eIF4G). Here we report the solution structure of the J-K region of this IRES and show that its stems are precisely organized to position protein-recognition bulges. This multisite interaction mechanism operates on an all-or-nothing principle in which all domains are required. This preorganization is accomplished by an 'adjuster module': a pentaloop motif that acts as a dual-sided docking station for base-pair receptors. Because subtle changes in the orientation abrogate protein capture, our study highlights how a viral RNA acquires affinity for a target protein.
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Affiliation(s)
- Shunsuke Imai
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Parimal Kumar
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, USA
| | | | - Victoria M D'Souza
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
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23
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Tanaka T, Matsumura S, Furuta H, Ikawa Y. Tecto-GIRz: Engineered Group I Ribozyme the Catalytic Ability of Which Can Be Controlled by Self-Dimerization. Chembiochem 2016; 17:1448-55. [DOI: 10.1002/cbic.201600190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Indexed: 01/17/2023]
Affiliation(s)
- Takahiro Tanaka
- Department of Chemistry and Biochemistry; Graduate School of Engineering; Kyushu University; Moto-oka 744 Nishi-ku Fukuoka 819-0395 Japan
| | - Shigeyoshi Matsumura
- Department of Chemistry; Graduate School of Science and Engineering; University of Toyama; Gofuku 3190 Toyama 930-8555 Japan
| | - Hiroyuki Furuta
- Department of Chemistry and Biochemistry; Graduate School of Engineering; Kyushu University; Moto-oka 744 Nishi-ku Fukuoka 819-0395 Japan
| | - Yoshiya Ikawa
- Department of Chemistry; Graduate School of Science and Engineering; University of Toyama; Gofuku 3190 Toyama 930-8555 Japan
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24
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Lozano G, Fernandez N, Martinez-Salas E. Modeling Three-Dimensional Structural Motifs of Viral IRES. J Mol Biol 2016; 428:767-776. [PMID: 26778619 DOI: 10.1016/j.jmb.2016.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 01/23/2023]
Abstract
RNA virus genomes are reservoirs of a wide diversity of RNA structural elements. In particular, specific regions of the viral genome have evolved to adopt specialized three-dimensional (3D) structures, which can act in concert with host factors and/or viral proteins to recruit the translation machinery on viral RNA using a mechanism that is independent on the 5' end. This strategy relies on cis-acting RNA sequences designated as internal ribosome entry site (IRES) elements. IRES elements that are found in the genome of different groups of RNA viruses perform the same function despite differing in primary sequence and secondary RNA structure and host factor requirement to recruit the translation machinery internally. Evolutionarily conserved motifs tend to preserve sequences in each group of RNA viruses impacting on RNA structure and RNA-protein interactions important for IRES function. However, due to the lack of sequence homology among genetically distant IRES elements, accurate modeling of 3D IRES structure is currently a challenging task. In addition, as a universal RNA motif unique to IRES elements has not been found, a better understanding of viral IRES structural motifs could greatly assist in the detection of IRES-like motifs hidden in genome sequences. The focus of this review is to describe recent advances in modeling viral IRES tertiary structural motifs and also novel approaches to detect sequences potentially folding as IRES-like motifs.
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Affiliation(s)
- Gloria Lozano
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas Universidad Autónoma de Madrid, Nicolas Cabrera 1, 28049 Madrid, Spain
| | - Noemi Fernandez
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas Universidad Autónoma de Madrid, Nicolas Cabrera 1, 28049 Madrid, Spain
| | - Encarnacion Martinez-Salas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas Universidad Autónoma de Madrid, Nicolas Cabrera 1, 28049 Madrid, Spain.
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25
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Eustermann S, Wu WF, Langelier MF, Yang JC, Easton LE, Riccio AA, Pascal JM, Neuhaus D. Structural Basis of Detection and Signaling of DNA Single-Strand Breaks by Human PARP-1. Mol Cell 2015; 60:742-754. [PMID: 26626479 PMCID: PMC4678113 DOI: 10.1016/j.molcel.2015.10.032] [Citation(s) in RCA: 224] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 09/26/2015] [Accepted: 10/16/2015] [Indexed: 01/10/2023]
Abstract
Poly(ADP-ribose)polymerase 1 (PARP-1) is a key eukaryotic stress sensor that responds in seconds to DNA single-strand breaks (SSBs), the most frequent genomic damage. A burst of poly(ADP-ribose) synthesis initiates DNA damage response, whereas PARP-1 inhibition kills BRCA-deficient tumor cells selectively, providing the first anti-cancer therapy based on synthetic lethality. However, the mechanism underlying PARP-1’s function remained obscure; inherent dynamics of SSBs and PARP-1’s multi-domain architecture hindered structural studies. Here we reveal the structural basis of SSB detection and how multi-domain folding underlies the allosteric switch that determines PARP-1’s signaling response. Two flexibly linked N-terminal zinc fingers recognize the extreme deformability of SSBs and drive co-operative, stepwise self-assembly of remaining PARP-1 domains to control the activity of the C-terminal catalytic domain. Automodifcation in cis explains the subsequent release of monomeric PARP-1 from DNA, allowing repair and replication to proceed. Our results provide a molecular framework for understanding PARP inhibitor action and, more generally, allosteric control of dynamic, multi-domain proteins. We identify the structural basis of DNA single-strand break detection by PARP-1 An NMR/X-ray approach reveals how multi-domain allostery underlies activity switch The molecular model of PARP-1 assembly couples damage detection to PAR signaling Automodification in cis releases enzyme so DNA repair and replication can proceed
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Affiliation(s)
- Sebastian Eustermann
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Wing-Fung Wu
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Marie-France Langelier
- Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA
| | - Ji-Chun Yang
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Laura E Easton
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Amanda A Riccio
- Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA
| | - John M Pascal
- Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA
| | - David Neuhaus
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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26
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Appasamy SD, Hamdani HY, Ramlan EI, Firdaus-Raih M. InterRNA: a database of base interactions in RNA structures. Nucleic Acids Res 2015; 44:D266-71. [PMID: 26553798 PMCID: PMC4702846 DOI: 10.1093/nar/gkv1186] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 10/24/2015] [Indexed: 11/17/2022] Open
Abstract
A major component of RNA structure stabilization are the hydrogen bonded interactions between the base residues. The importance and biological relevance for large clusters of base interactions can be much more easily investigated when their occurrences have been systematically detected, catalogued and compared. In this paper, we describe the database InterRNA (INTERactions in RNA structures database—http://mfrlab.org/interrna/) that contains records of known RNA 3D motifs as well as records for clusters of bases that are interconnected by hydrogen bonds. The contents of the database were compiled from RNA structural annotations carried out by the NASSAM (http://mfrlab.org/grafss/nassam) and COGNAC (http://mfrlab.org/grafss/cognac) computer programs. An analysis of the database content and comparisons with the existing corpus of knowledge regarding RNA 3D motifs clearly show that InterRNA is able to provide an extension of the annotations for known motifs as well as able to provide novel interactions for further investigations.
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Affiliation(s)
- Sri Devan Appasamy
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Hazrina Yusof Hamdani
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Effirul Ikhwan Ramlan
- Department of Artificial Intelligence, Faculty of Computer Science and Information Technology, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohd Firdaus-Raih
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
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27
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Abstract
![]()
Influenza A is an RNA virus with
a genome of eight negative sense
segments. Segment 7 mRNA contains a 3′ splice site for alternative
splicing to encode the essential M2 protein. On the basis of sequence
alignment and chemical mapping experiments, the secondary structure
surrounding the 3′ splice site has an internal loop, adenine
bulge, and hairpin loop when it is in the hairpin conformation that
exposes the 3′ splice site. We report structural features of
a three-dimensional model of the hairpin derived from nuclear magnetic
resonance spectra and simulated annealing with restrained molecular
dynamics. Additional insight was provided by modeling based on 1H chemical shifts. The internal loop containing the 3′
splice site has a dynamic guanosine and a stable imino (cis Watson–Crick/Watson–Crick) GA pair. The adenine bulge
also appears to be dynamic with the A either stacked in the stem or
forming a base triple with a Watson–Crick GC pair. The hairpin
loop is a GAAA tetraloop closed by an AC pair.
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Affiliation(s)
- Jonathan L Chen
- †Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Scott D Kennedy
- ‡Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Douglas H Turner
- †Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.,§Center for RNA Biology, University of Rochester, Rochester, New York 14627, United States
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28
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Ingle S, Azad RN, Jain SS, Tullius TD. Chemical probing of RNA with the hydroxyl radical at single-atom resolution. Nucleic Acids Res 2014; 42:12758-67. [PMID: 25313156 PMCID: PMC4227780 DOI: 10.1093/nar/gku934] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 09/17/2014] [Accepted: 09/24/2014] [Indexed: 12/02/2022] Open
Abstract
While hydroxyl radical cleavage is widely used to map RNA tertiary structure, lack of mechanistic understanding of strand break formation limits the degree of structural insight that can be obtained from this experiment. Here, we determine how individual ribose hydrogens of sarcin/ricin loop RNA participate in strand cleavage. We find that substituting deuterium for hydrogen at a ribose 5'-carbon produces a kinetic isotope effect on cleavage; the major cleavage product is an RNA strand terminated by a 5'-aldehyde. We conclude that hydroxyl radical abstracts a 5'-hydrogen atom, leading to RNA strand cleavage. We used this approach to obtain structural information for a GUA base triple, a common tertiary structural feature of RNA. Cleavage at U exhibits a large 5' deuterium kinetic isotope effect, a potential signature of a base triple. Others had noted a ribose-phosphate hydrogen bond involving the G 2'-OH and the U phosphate of the GUA triple, and suggested that this hydrogen bond contributes to backbone rigidity. Substituting deoxyguanosine for G, to eliminate this hydrogen bond, results in a substantial decrease in cleavage at G and U of the triple. We conclude that this hydrogen bond is a linchpin of backbone structure around the triple.
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Affiliation(s)
- Shakti Ingle
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Robert N Azad
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Swapan S Jain
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Thomas D Tullius
- Department of Chemistry, Boston University, Boston, MA 02215, USA Program in Bioinformatics, Boston University, Boston, MA 02215, USA
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29
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Analysis of stacking overlap in nucleic acid structures: algorithm and application. J Comput Aided Mol Des 2014; 28:851-67. [DOI: 10.1007/s10822-014-9767-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 06/23/2014] [Indexed: 10/25/2022]
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30
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Lim ES, Cao S, Holtz LR, Antonio M, Stine OC, Wang D. Discovery of rosavirus 2, a novel variant of a rodent-associated picornavirus, in children from The Gambia. Virology 2014; 454-455:25-33. [PMID: 24725928 DOI: 10.1016/j.virol.2014.01.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 01/16/2014] [Accepted: 01/22/2014] [Indexed: 12/18/2022]
Abstract
We describe the identification of a novel picornavirus recovered from the fecal specimen of a child in The Gambia, provisionally named rosavirus 2. Comparison of the rosavirus 2 complete genome demonstrated 71.9% nucleotide identity to its closest relative rosavirus M-7, an unclassified picornavirus identified from rodent fecal material. A unique RNA structure was predicted in the 3' UTR of rosavirus 2 that was conserved with rosavirus M-7 and cadiciviruses. We detected rosavirus 2 in four pediatric fecal specimens (0.55% prevalence) in a Gambian diarrheal case-control cohort, but we did not detect it in a panel of 634 pediatric diarrheal stool specimens from the USA. There was no statistical evidence that rosavirus 2 was associated with diarrheal cases. This study broadens our understanding of unknown viruses present in children in developing country settings.
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Affiliation(s)
- Efrem S Lim
- Departments of Molecular Microbiology and Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Song Cao
- Departments of Molecular Microbiology and Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Lori R Holtz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | | | - O Colin Stine
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David Wang
- Departments of Molecular Microbiology and Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA.
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31
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Nayak RK, Van Orden A. Counterion and polythymidine loop-length-dependent folding and thermodynamic stability of DNA hairpins reveal the unusual counterion-dependent stability of tetraloop hairpins. J Phys Chem B 2013; 117:13956-66. [PMID: 24144397 DOI: 10.1021/jp404832d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Stem-loop DNA hairpins containing a 5-base-pair (bp) stem and single-stranded polythymidine loop were investigated using thermodynamic melting analysis and stopped-flow kinetics. These studies revealed the thermodynamic stability and folding kinetics as a function of loop length and counterion concentration. Our results show the unusually high thermodynamic stability for tetraloop or 4 poly(dT) loop hairpin as compared with longer loop length hairpins. Furthermore, this exceptional stability is highly counterion-dependent. For example, in the higher counterion concentration regime of 50 mM NaCl and above, the tetraloop hairpin displays enhanced stability as compared with longer loop length hairpins. However, at lower counterion concentration of 25 mM NaCl and below, the thermal stability of tetraloop hairpin is consistent with the longer loop hairpins. The enhanced stability of tetraloop hairpins at higher counterion concentration can be explained on the basis of the combined entropic effect of loop closure as well as base stacking in the loop regions. The stability of longer loop length hairpins at all counterion concentrations as well as tetraloop hairpin at lower counterion concentration can be explained on the basis of entropic effect of loop closure alone. The thermodynamic parameters at lower and higher counterion concentrations were determined to quantify the enhanced stability of base-stacking effects occurring at higher counterion concentrations. For example, for 100 mM NaCl, excess Gibbs energy and enthalpy due to base stacking within the tetraloops were measured to be -1.2 ± 0.14 and -3.28 ± 0.32 kcal/mol, respectively, whereas, no excess of Gibbs energy and enthalpy was observed for 0, 5, 10, and 25 mM NaCl. These findings suggest significant base-stacking interactions occurring in the loop region of the tetraloop hairpins at higher counterion concentration and less significant base-stacking interactions in the lower counterion concentration regime. We suggest that at higher counterion concentrations, hydrophobic collapse of the nucleotides in the loop may be enhanced due to the increased polarity of the solvent, thereby enhancing base-stacking interactions that contribute to unusually high stability.
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Affiliation(s)
- Rajesh K Nayak
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States
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32
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Abstract
Nearly two decades after Westhof and Michel first proposed that RNA tetraloops may interact with distal helices, tetraloop–receptor interactions have been recognized as ubiquitous elements of RNA tertiary structure. The unique architecture of GNRA tetraloops (N=any nucleotide, R=purine) enables interaction with a variety of receptors, e.g., helical minor grooves and asymmetric internal loops. The most common example of the latter is the GAAA tetraloop–11 nt tetraloop receptor motif. Biophysical characterization of this motif provided evidence for the modularity of RNA structure, with applications spanning improved crystallization methods to RNA tectonics. In this review, we identify and compare types of GNRA tetraloop–receptor interactions. Then we explore the abundance of structural, kinetic, and thermodynamic information on the frequently occurring and most widely studied GAAA tetraloop–11 nt receptor motif. Studies of this interaction have revealed powerful paradigms for structural assembly of RNA, as well as providing new insights into the roles of cations, transition states and protein chaperones in RNA folding pathways. However, further research will clearly be necessary to characterize other tetraloop–receptor and long-range tertiary binding interactions in detail – an important milestone in the quantitative prediction of free energy landscapes for RNA folding.
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33
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Halder S, Bhattacharyya D. RNA structure and dynamics: a base pairing perspective. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 113:264-83. [PMID: 23891726 DOI: 10.1016/j.pbiomolbio.2013.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/25/2013] [Accepted: 07/16/2013] [Indexed: 12/12/2022]
Abstract
RNA is now known to possess various structural, regulatory and enzymatic functions for survival of cellular organisms. Functional RNA structures are generally created by three-dimensional organization of small structural motifs, formed by base pairing between self-complementary sequences from different parts of the RNA chain. In addition to the canonical Watson-Crick or wobble base pairs, several non-canonical base pairs are found to be crucial to the structural organization of RNA molecules. They appear within different structural motifs and are found to stabilize the molecule through long-range intra-molecular interactions between basic structural motifs like double helices and loops. These base pairs also impart functional variation to the minor groove of A-form RNA helices, thus forming anchoring site for metabolites and ligands. Non-canonical base pairs are formed by edge-to-edge hydrogen bonding interactions between the bases. A large number of theoretical studies have been done to detect and analyze these non-canonical base pairs within crystal or NMR derived structures of different functional RNA. Theoretical studies of these isolated base pairs using ab initio quantum chemical methods as well as molecular dynamics simulations of larger fragments have also established that many of these non-canonical base pairs are as stable as the canonical Watson-Crick base pairs. This review focuses on the various structural aspects of non-canonical base pairs in the organization of RNA molecules and the possible applications of these base pairs in predicting RNA structures with more accuracy.
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Affiliation(s)
- Sukanya Halder
- Biophysics division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064, India
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34
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Kührová P, Banáš P, Best RB, Šponer J, Otyepka M. Computer Folding of RNA Tetraloops? Are We There Yet? J Chem Theory Comput 2013; 9:2115-25. [DOI: 10.1021/ct301086z] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Petra Kührová
- Regional Centre of Advanced Technologies
and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies
and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
| | - Robert B. Best
- Laboratory of Chemical Physics,
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520,
United States
| | - Jiří Šponer
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
- CEITEC − Central European
Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies
and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska
135, 612 65 Brno, Czech Republic
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35
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Ishikawa J, Furuta H, Ikawa Y. An in vitro-selected RNA receptor for the GAAC loop: modular receptor for non-GNRA-type tetraloop. Nucleic Acids Res 2013; 41:3748-59. [PMID: 23382175 PMCID: PMC3616724 DOI: 10.1093/nar/gkt040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Although artificial RNA motifs that can functionally replace the GNRA/receptor interaction, a class of RNA-RNA interacting motifs, were isolated from RNA libraries and used to generate designer RNA structures, receptors for non-GNRA tetraloops have not been found in nature or selected from RNA libraries. In this study, we report successful isolation of a receptor motif interacting with GAAC, a non-GNRA tetraloop, from randomized sequences embedded in a catalytic RNA. Biochemical characterization of the GAAC/receptor interacting motif within three structural contexts showed its binding affinity, selectivity and structural autonomy. The motif has binding affinity comparable with that of a GNRA/receptor, selectivity orthogonal to GNRA/receptors and structural autonomy even in a large RNA context. These features would be advantageous for usage of the motif as a building block for designer RNAs. The isolated motif can also be used as a query sequence to search for unidentified naturally occurring GANC receptor motifs.
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Affiliation(s)
- Junya Ishikawa
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan
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36
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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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37
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Jung S, Schlick T. Candidate RNA structures for domain 3 of the foot-and-mouth-disease virus internal ribosome entry site. Nucleic Acids Res 2012; 41:1483-95. [PMID: 23275533 PMCID: PMC3561949 DOI: 10.1093/nar/gks1302] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The foot-and-mouth-disease virus (FMDV) utilizes non-canonical translation initiation for viral protein synthesis, by forming a specific RNA structure called internal ribosome entry site (IRES). Domain 3 in FMDV IRES is phylogenetically conserved and highly structured; it contains four-way junctions where intramolecular RNA–RNA interactions serve as a scaffold for the RNA to fold for efficient IRES activity. Although the 3D structure of domain 3 is crucial to exploring and deciphering the initiation mechanism of translation, little is known. Here, we employ a combination of various modeling approaches to propose candidate tertiary structures for the apical region of domain 3, thought to be crucial for IRES function. We begin by modeling junction topology candidates and build atomic 3D models consistent with available experimental data. We then investigate each of the four candidate 3D structures by molecular dynamics simulations to determine the most energetically favorable configurations and to analyze specific tertiary interactions. Only one model emerges as viable containing not only the specific binding site for the GNRA tetraloop but also helical arrangements which enhance the stability of domain 3. These collective findings, together with available experimental data, suggest a plausible theoretical tertiary structure of the apical region in FMDV IRES domain 3.
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Affiliation(s)
- Segun Jung
- Department of Chemistry, Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012, USA
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38
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Zhao Q, Huang HC, Nagaswamy U, Xia Y, Gao X, Fox GE. UNAC tetraloops: to what extent do they mimic GNRA tetraloops? Biopolymers 2012; 97:617-28. [PMID: 22605553 DOI: 10.1002/bip.22049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The structures of four small RNAs each containing a different version of the UNAC loop were determined in solution using NMR spectroscopy and restrained molecular dynamics. The UMAC tetraloops (where M is A or C) exhibited a typical GNRA fold including at least one hydrogen bond between the first U and fourth C. In contrast, UGAC and UUAC tetraloops have a different orientation of the first and fourth residues, such that they do not closely mimic the GNRA fold. Although the UMAC tetraloops are excellent structural mimics of the GNRA tetraloop backbone, sequence comparisons typically do not reveal co-variation between the two loop types. The limited covariation is attributed to differences in the location of potential hydrogen bond donors and acceptors as a result of the replacement of the terminal A of GNRA with C in the UMAC version. Thus, UMAC loops do not readily form the common GNRA tetraloop-receptor interaction. The loop at positions 863-866 in E. coli 16S ribosomal RNA appears to be a major exception. However, in this case the GNRA loop does not in fact engage in the usual base to backbone tertiary interactions. In summary, UMAC loops are not just an alternative sequence version of the GNRA loop family, but instead they expand the types of interactions, or lack thereof, that are possible. From a synthetic biology perspective their inclusion in an artificial RNA may allow the establishment of a stable loop structure while minimizing unwanted long range interactions or permitting alternative long-range interactions. © 2012 Wiley Periodicals, Inc. Biopolymers 97: 617-628, 2012.
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Affiliation(s)
- Qin Zhao
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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39
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Abstract
Transitions between the different conformational states play a critical role in many RNA catalytic and regulatory functions. In this study, we use the Kinetic Monte Carlo method to investigate the kinetic mechanism for the conformational switches between bistable RNA hairpins. We find three types of conformational switch pathways for RNA hairpins: refolding after complete unfolding, folding through basepair-exchange pathways and through pseudoknot-assisted pathways, respectively. The result of the competition between the three types of pathways depends mainly on the location of the rate-limiting base stacks (such as the GC base stacks) in the structures. Depending on the structural relationships between the two bistable hairpins, the conformational switch can follow single or multiple dominant pathways. The predicted folding pathways are supported by the activation energy results derived from the Arrhenius plot as well as the NMR spectroscopy data.
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Affiliation(s)
- Xiaojun XU
- Department of Physics and Department of Biochemistry University of Missouri, Columbia, MO 65211
| | - Shi-Jie CHEN
- Department of Physics and Department of Biochemistry University of Missouri, Columbia, MO 65211
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40
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Henriksen NM, Davis DR, Cheatham TE. Molecular dynamics re-refinement of two different small RNA loop structures using the original NMR data suggest a common structure. JOURNAL OF BIOMOLECULAR NMR 2012; 53:321-39. [PMID: 22714631 PMCID: PMC3405240 DOI: 10.1007/s10858-012-9642-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 05/24/2012] [Indexed: 06/01/2023]
Abstract
Restrained molecular dynamics simulations are a robust, though perhaps underused, tool for the end-stage refinement of biomolecular structures. We demonstrate their utility-using modern simulation protocols, optimized force fields, and inclusion of explicit solvent and mobile counterions-by re-investigating the solution structures of two RNA hairpins that had previously been refined using conventional techniques. The structures, both domain 5 group II intron ribozymes from yeast ai5γ and Pylaiella littoralis, share a nearly identical primary sequence yet the published 3D structures appear quite different. Relatively long restrained MD simulations using the original NMR restraint data identified the presence of a small set of violated distance restraints in one structure and a possibly incorrect trapped bulge nucleotide conformation in the other structure. The removal of problematic distance restraints and the addition of a heating step yielded representative ensembles with very similar 3D structures and much lower pairwise RMSD values. Analysis of ion density during the restrained simulations helped to explain chemical shift perturbation data published previously. These results suggest that restrained MD simulations, with proper caution, can be used to "update" older structures or aid in the refinement of new structures that lack sufficient experimental data to produce a high quality result. Notable cautions include the need for sufficient sampling, awareness of potential force field bias (such as small angle deviations with the current AMBER force fields), and a proper balance between the various restraint weights.
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Affiliation(s)
- Niel M Henriksen
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, 2000 East 30 South Skaggs 201, Salt Lake City, UT 84112, USA.
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41
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Hamdani HY, Appasamy SD, Willett P, Artymiuk PJ, Firdaus-Raih M. NASSAM: a server to search for and annotate tertiary interactions and motifs in three-dimensional structures of complex RNA molecules. Nucleic Acids Res 2012; 40:W35-41. [PMID: 22661578 PMCID: PMC3394293 DOI: 10.1093/nar/gks513] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Similarities in the 3D patterns of RNA base interactions or arrangements can provide insights into their functions and roles in stabilization of the RNA 3D structure. Nucleic Acids Search for Substructures and Motifs (NASSAM) is a graph theoretical program that can search for 3D patterns of base arrangements by representing the bases as pseudo-atoms. The geometric relationship of the pseudo-atoms to each other as a pattern can be represented as a labeled graph where the pseudo-atoms are the graph’s nodes while the edges are the inter-pseudo-atomic distances. The input files for NASSAM are PDB formatted 3D coordinates. This web server can be used to identify matches of base arrangement patterns in a query structure to annotated patterns that have been reported in the literature or that have possible functional and structural stabilization implications. The NASSAM program is freely accessible without any login requirement at http://mfrlab.org/grafss/nassam/.
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Affiliation(s)
- Hazrina Y Hamdani
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Malaysia
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42
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Wallace JG, Zhou Z, Breaker RR. OLE RNA protects extremophilic bacteria from alcohol toxicity. Nucleic Acids Res 2012; 40:6898-907. [PMID: 22561371 PMCID: PMC3413148 DOI: 10.1093/nar/gks352] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OLE (Ornate, Large, Extremophilic) RNAs represent a recently discovered non-coding RNA class found in extremophilic anaerobic bacteria, including certain human pathogens. OLE RNAs exhibit several unusual characteristics that indicate a potentially novel function, including exceptionally high expression and localization to cell membranes via interaction with a protein partner called OLE-associated protein (OAP). In the current study, new genetic and phenotypic characteristics of OLE RNA from Bacillus halodurans C-125 were established. OLE RNA is transcribed at high levels from its own promoter under normal growth conditions and the transcript is exceptionally stable compared to most other RNAs. Expression is increased by ∼7-fold when cells are exposed to near lethal concentrations of short-chain alcohols such as ethanol or methanol. Strains wherein the genes for OLE and/or OAP are deleted are more susceptible to growth inhibition by alcohol and also become more sensitive to cold. Normal growth characteristics can be restored by expressing the genes for OLE and OAP from plasmids or from elsewhere on the chromosome. Our findings confirm a functional link between OLE and OAP and reveal the importance of a large non-coding RNA in the response to alcohol-induced stress.
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Affiliation(s)
- Jason G Wallace
- Department of Molecular, Cellular and Developmental Biology, Department of Molecular Biophysics and Biochemistry and Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
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43
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Shen Y, Wong HS, Zhang S, Yu Z. Feature-based 3D motif filtering for ribosomal RNA. ACTA ACUST UNITED AC 2011; 27:2828-35. [PMID: 21873638 DOI: 10.1093/bioinformatics/btr495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
MOTIVATION RNA 3D motifs are recurrent substructures in an RNA subunit and are building blocks of the RNA architecture. They play an important role in binding proteins and consolidating RNA tertiary structures. RNA 3D motif searching consists of two steps: candidate generation and candidate filtering. We proposed a novel method, known as Feature-based RNA Motif Filtering (FRMF), for identifying motifs based on a set of moment invariants and the Earth Mover's Distance in the second step. RESULTS A positive set of RNA motifs belonging to six characteristic types, with eight subtypes occurring in HM 50S, is compiled by us. The proposed method is validated on this representative set. FRMF successfully finds most of the positive fragments. Besides the proposed new method and the compiled positive set, we also recognize some new motifs, in particular a π-turn and some non-standard A-minor motifs are found. These newly discovered motifs provide more information about RNA structure conformation. AVAILABILITY Matlab code can be downloaded from www.cs.cityu.edu.hk/~yingshen/FRMF.html CONTACT cshswong@cityu.edu.hk SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Ying Shen
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
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Denning EJ, Priyakumar UD, Nilsson L, MacKerell AD. Impact of 2'-hydroxyl sampling on the conformational properties of RNA: update of the CHARMM all-atom additive force field for RNA. J Comput Chem 2011; 32:1929-43. [PMID: 21469161 PMCID: PMC3082605 DOI: 10.1002/jcc.21777] [Citation(s) in RCA: 288] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/24/2011] [Accepted: 01/30/2011] [Indexed: 01/02/2023]
Abstract
Here, we present an update of the CHARMM27 all-atom additive force field for nucleic acids that improves the treatment of RNA molecules. The original CHARMM27 force field parameters exhibit enhanced Watson-Crick base pair opening which is not consistent with experiment, whereas analysis of molecular dynamics (MD) simulations show the 2'-hydroxyl moiety to almost exclusively sample the O3' orientation. Quantum mechanical (QM) studies of RNA related model compounds indicate the energy minimum associated with the O3' orientation to be too favorable, consistent with the MD results. Optimization of the dihedral parameters dictating the energy of the 2'-hydroxyl proton targeting the QM data yielded several parameter sets, which sample both the base and O3' orientations of the 2'-hydroxyl to varying degrees. Selection of the final dihedral parameters was based on reproduction of hydration behavior as related to a survey of crystallographic data and better agreement with experimental NMR J-coupling values. Application of the model, designated CHARMM36, to a collection of canonical and noncanonical RNA molecules reveals overall improved agreement with a range of experimental observables as compared to CHARMM27. The results also indicate the sensitivity of the conformational heterogeneity of RNA to the orientation of the 2'-hydroxyl moiety and support a model whereby the 2'-hydroxyl can enhance the probability of conformational transitions in RNA.
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Affiliation(s)
- Elizabeth J. Denning
- Department of Pharmaceutical Sciences, School of Pharmacy, University
of Maryland, Baltimore, MD 21201
| | - U. Deva Priyakumar
- Department of Pharmaceutical Sciences, School of Pharmacy, University
of Maryland, Baltimore, MD 21201
| | - Lennart Nilsson
- Department of Pharmaceutical Sciences, School of Pharmacy, University
of Maryland, Baltimore, MD 21201
| | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University
of Maryland, Baltimore, MD 21201
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Fernández N, Fernandez-Miragall O, Ramajo J, García-Sacristán A, Bellora N, Eyras E, Briones C, Martínez-Salas E. Structural basis for the biological relevance of the invariant apical stem in IRES-mediated translation. Nucleic Acids Res 2011; 39:8572-85. [PMID: 21742761 PMCID: PMC3201876 DOI: 10.1093/nar/gkr560] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
RNA structure plays a fundamental role in internal initiation of translation. Picornavirus internal ribosome entry site (IRES) are long, efficient cis-acting elements that recruit the ribosome to internal mRNA sites. However, little is known about long-range constraints determining the IRES RNA structure. Here, we sought to investigate the functional and structural relevance of the invariant apical stem of a picornavirus IRES. Mutation of this apical stem revealed better performance of G:C compared with C:G base pairs, demonstrating that the secondary structure solely is not sufficient for IRES function. In turn, mutations designed to disrupt the stem abolished IRES activity. Lack of tolerance to accept genetic variability in the apical stem was supported by the presence of coupled covariations within the adjacent stem-loops. SHAPE structural analysis, gel mobility-shift and microarrays-based RNA accessibility revealed that the apical stem contributes to maintain IRES RNA structure through the generation of distant interactions between two adjacent stem-loops. Our results demonstrate that a highly interactive structure constrained by distant interactions involving invariant G:C base pairs plays a key role in maintaining the RNA conformation necessary for IRES-mediated translation.
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Affiliation(s)
- Noemí Fernández
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Ishikawa J, Fujita Y, Maeda Y, Furuta H, Ikawa Y. GNRA/receptor interacting modules: Versatile modular units for natural and artificial RNA architectures. Methods 2011; 54:226-38. [DOI: 10.1016/j.ymeth.2010.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 12/08/2010] [Accepted: 12/08/2010] [Indexed: 12/25/2022] Open
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Abstract
Unlike proteins, the RNA backbone has numerous degrees of freedom (eight, if one counts the sugar pucker), making RNA modeling, structure building and prediction a multidimensional problem of exceptionally high complexity. And yet RNA tertiary structures are not infinite in their structural morphology; rather, they are built from a limited set of discrete units. In order to reduce the dimensionality of the RNA backbone in a physically reasonable way, a shorthand notation was created that reduced the RNA backbone torsion angles to two (η and θ, analogous to φ and ψ in proteins). When these torsion angles are calculated for nucleotides in a crystallographic database and plotted against one another, one obtains a plot analogous to a Ramachandran plot (the η/θ plot), with highly populated and unpopulated regions. Nucleotides that occupy proximal positions on the plot have identical structures and are found in the same units of tertiary structure. In this review, we describe the statistical validation of the η/θ formalism and the exploration of features within the η/θ plot. We also describe the application of the η/θ formalism in RNA motif discovery, structural comparison, RNA structure building and tertiary structure prediction. More than a tool, however, the η/θ formalism has provided new insights into RNA structure itself, revealing its fundamental components and the factors underlying RNA architectural form.
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Plantinga MJ, Korennykh AV, Piccirilli JA, Correll CC. The ribotoxin restrictocin recognizes its RNA substrate by selective engagement of active site residues. Biochemistry 2011; 50:3004-13. [PMID: 21417210 PMCID: PMC3071035 DOI: 10.1021/bi1018336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
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Restrictocin and related fungal endoribonucleases from the α-sarcin family site-specifically cleave the sarcin/ricin loop (SRL) on the ribosome to inhibit translation and ultimately trigger cell death. Previous studies showed that the SRL folds into a bulged-G motif and tetraloop, with restrictocin achieving a specificity of ∼1000-fold by recognizing both motifs only after the initial binding step. Here, we identify contacts within the protein−RNA interface and determine the extent to which each one contributes to enzyme specificity by examining the effect of protein mutations on the cleavage of the SRL substrate compared to a variety of other RNA substrates. As with other biomolecular interfaces, only a subset of contacts contributes to specificity. One contact of this subset is critical, with the H49A mutation resulting in quantitative loss of specificity. Maximum catalytic activity occurs when both motifs of the SRL are present, with the major contribution involving the bulged-G motif recognized by three lysine residues located adjacent to the active site: K110, K111, and K113. Our findings support a kinetic proofreading mechanism in which the active site residues H49 and, to a lesser extent, Y47 make greater catalytic contributions to SRL cleavage than to suboptimal substrates. This systematic and quantitative analysis begins to elucidate the principles governing RNA recognition by a site-specific endonuclease and may thus serve as a mechanistic model for investigating other RNA modifying enzymes.
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Affiliation(s)
- Matthew J Plantinga
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
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Banáš P, Hollas D, Zgarbová M, Jurečka P, Orozco M, Cheatham TE, Šponer J, Otyepka M. Performance of Molecular Mechanics Force Fields for RNA Simulations: Stability of UUCG and GNRA Hairpins. J Chem Theory Comput 2010; 6:3836-3849. [DOI: 10.1021/ct100481h] [Citation(s) in RCA: 293] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Daniel Hollas
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Marie Zgarbová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Modesto Orozco
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Thomas E. Cheatham
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Jiří Šponer
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, tr. 17. listopadu 12, 771 46 Olomouc, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic, Joint Research Program in Computational Biology, Institut de Recerca Biomédica and Barcelona Superocomputing Center, Baldiri i Reixac 10, Barcelona 08028, Spain, Jordi Girona 31, Barcelona 08028, Spain
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Fernández N, García-Sacristán A, Ramajo J, Briones C, Martínez-Salas E. Structural analysis provides insights into the modular organization of picornavirus IRES. Virology 2010; 409:251-61. [PMID: 21056890 DOI: 10.1016/j.virol.2010.10.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 09/12/2010] [Accepted: 10/08/2010] [Indexed: 10/18/2022]
Abstract
Picornavirus RNA translation is driven by the internal ribosome entry site (IRES) element. The impact of RNA structure on the foot-and-mouth disease virus (FMDV) IRES activity has been analyzed using Selective 2'Hydroxyl Acylation analyzed by Primer Extension (SHAPE) and high throughput analysis of RNA conformation by antisense oligonucleotides printed on microarrays. SHAPE reactivity revealed the self-folding capacity of domain 3 and evidenced a change of RNA structure in a defective GNRA mutant. A modified RNA conformation of this mutant was also evidenced by RNA accessibility to oligonucleotides. Interestingly, comparison of nucleotide reactivity with RNA accessibility revealed that SHAPE reactive nucleotides corresponding to the GNRA motif were not accessible to their respective target oligonucleotides. The differential response was observed both in domain 3 and the entire IRES. Our results demonstrate distant effects of the GNRA motif in the domain 3 RNA conformation, and highlight the modular organization of a picornavirus IRES.
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Affiliation(s)
- Noemí Fernández
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Cantoblanco 28049 Madrid, Spain
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