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Vögele J, Duchardt-Ferner E, Bains JK, Knezic B, Wacker A, Sich C, Weigand J, Šponer J, Schwalbe H, Krepl M, Wöhnert J. Structure of an internal loop motif with three consecutive U•U mismatches from stem-loop 1 in the 3'-UTR of the SARS-CoV-2 genomic RNA. Nucleic Acids Res 2024; 52:6687-6706. [PMID: 38783391 PMCID: PMC11194097 DOI: 10.1093/nar/gkae349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
The single-stranded RNA genome of SARS-CoV-2 is highly structured. Numerous helical stem-loop structures interrupted by mismatch motifs are present in the functionally important 5'- and 3'-UTRs. These mismatches modulate local helical geometries and feature unusual arrays of hydrogen bonding donor and acceptor groups. However, their conformational and dynamical properties cannot be directly inferred from chemical probing and are difficult to predict theoretically. A mismatch motif (SL1-motif) consisting of three consecutive U•U base pairs is located in stem-loop 1 of the 3'-UTR. We combined NMR-spectroscopy and MD-simulations to investigate its structure and dynamics. All three U•U base pairs feature two direct hydrogen bonds and are as stable as Watson-Crick A:U base pairs. Plasmodium falciparum 25S rRNA contains a triple U•U mismatch motif (Pf-motif) differing from SL1-motif only with respect to the orientation of the two closing base pairs. Interestingly, while the geometry of the outer two U•U mismatches was identical in both motifs the preferred orientation of the central U•U mismatch was different. MD simulations and potassium ion titrations revealed that the potassium ion-binding mode to the major groove is connected to the different preferred geometries of the central base pair in the two motifs.
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Affiliation(s)
- Jennifer Vögele
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Elke Duchardt-Ferner
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Jasleen Kaur Bains
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Bozana Knezic
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Anna Wacker
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Christian Sich
- Volkswagen AG, Brieffach 1617/0, 38436 Wolfsburg, Germany
| | - Julia E Weigand
- Institute of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037 Marburg, Germany
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 00 Brno, Czech Republic
| | - Harald Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 00 Brno, Czech Republic
| | - Jens Wöhnert
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
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2
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Wang SC, Chen YT, Satange R, Chu JW, Hou MH. Structural basis for water modulating RNA duplex formation in the CUG repeats of myotonic dystrophy type 1. J Biol Chem 2023:104864. [PMID: 37245780 PMCID: PMC10316006 DOI: 10.1016/j.jbc.2023.104864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/19/2023] [Accepted: 05/21/2023] [Indexed: 05/30/2023] Open
Abstract
Secondary structures formed by expanded CUG RNA are involved in the pathobiology of myotonic dystrophy type 1. Understanding the molecular basis of toxic RNA structures can provide insights into the mechanism of disease pathogenesis and accelerate the drug discovery process. Here, we report the crystal structure of CUG repeat RNA containing three U-U mismatches between C-G and G-C base pairs. The CUG RNA crystallizes as an A-form duplex, with the first and third U-U mismatches adopting a water-mediated asymmetric mirror isoform geometry. We found for the first time that a symmetric, water-bridged U-H2O-U mismatch is well tolerated within the CUG RNA duplex, which was previously suspected but not observed. The new water-bridged U-U mismatch resulted in high base-pair opening and single-sided cross-strand stacking interactions, which in turn dominate the CUG RNA structure. Furthermore, we performed molecular dynamics (MD) simulations that complemented the structural findings and proposed that the first and third U-U mismatches are interchangeable conformations, while the central water-bridged U-U mismatch represents an intermediate state that modulates the RNA duplex conformation. Collectively, the new structural features provided in this work are important for understanding the recognition of U-U mismatches in CUG repeats by external ligands such as proteins or small molecules.
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Affiliation(s)
- Shun-Ching Wang
- Institute of Genomics and Bioinformatics; National Chung Hsing University, Taichung 402, Taiwan; Ph.D. Program in Medical Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi-Tsao Chen
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 30068 Taiwan
| | - Roshan Satange
- Institute of Genomics and Bioinformatics; National Chung Hsing University, Taichung 402, Taiwan
| | - Jhih-Wei Chu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 30068 Taiwan; Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068 Taiwan; Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, 30068 Taiwan.
| | - Ming-Hon Hou
- Institute of Genomics and Bioinformatics; National Chung Hsing University, Taichung 402, Taiwan; Ph.D. Program in Medical Biotechnology, National Chung Hsing University, Taichung 402, Taiwan; Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.
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3
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Onuchic PL, Milin AN, Alshareedah I, Deniz AA, Banerjee PR. Divalent cations can control a switch-like behavior in heterotypic and homotypic RNA coacervates. Sci Rep 2019; 9:12161. [PMID: 31434954 PMCID: PMC6704260 DOI: 10.1038/s41598-019-48457-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/06/2019] [Indexed: 01/30/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) of RNA-protein complexes plays a major role in the cellular function of membraneless organelles (MLOs). MLOs are sensitive to changes in cellular conditions, such as fluctuations in cytoplasmic ion concentrations. To investigate the effect of these changes on MLOs, we studied the influence of divalent cations on the physical and chemical properties of RNA coacervates. Using a model system comprised of an arginine-rich peptide and RNA, we predicted and observed that variations in signaling cations exert interaction-dependent effects on RNA LLPS. Changing the ionic environment has opposing effects on the propensity for heterotypic peptide-RNA and homotypic RNA LLPS, which results in a switch between coacervate types. Furthermore, divalent ion variations continuously tune the microenvironments and fluid properties of heterotypic and homotypic droplets. Our results may provide a general mechanism for modulating the biochemical environment of RNA coacervates in a cellular context.
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Affiliation(s)
- Paulo L Onuchic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, 92037, USA
| | - Anthony N Milin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, 92037, USA
| | - Ibraheem Alshareedah
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Ashok A Deniz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, 92037, USA.
| | - Priya R Banerjee
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA.
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4
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Nichols PJ, Born A, Henen MA, Strotz D, Celestine CN, Güntert P, Vögeli B. Extending the Applicability of Exact Nuclear Overhauser Enhancements to Large Proteins and RNA. Chembiochem 2018; 19:1695-1701. [PMID: 29883016 DOI: 10.1002/cbic.201800237] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Indexed: 01/24/2023]
Abstract
Distance-dependent nuclear Overhauser enhancements (NOEs) are one of the most popular and important experimental restraints for calculating NMR structures. Despite this, they are mostly employed as semiquantitative upper distance bounds, and this discards the wealth of information that is encoded in the cross-relaxation rate constant. Information that is lost includes exact distances between protons and dynamics that occur on the sub-millisecond timescale. Our recently introduced exact measurement of the NOE (eNOE) requires little additional experimental effort relative to other NMR observables. So far, we have used eNOEs to calculate multistate ensembles of proteins up to approximately 150 residues. Here, we briefly revisit eNOE methodology and present two new directions for the use of eNOEs: applications to large proteins and RNA.
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Affiliation(s)
- Parker J Nichols
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Alexandra Born
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Morkos A Henen
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO, 80045, USA
- Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Dean Strotz
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
| | - Chi N Celestine
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, 75123, Uppsala, Sweden
| | - Peter Güntert
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland
- Institute of Biophysical Chemistry, Goethe Universität Frankfurt, Max-von-Laue-Strasse 9, 60438, Frankfurt am Main, Germany
- Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji, Tokyo, 192-0397, Japan
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora, CO, 80045, USA
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5
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Chen JL, VanEtten DM, Fountain MA, Yildirim I, Disney MD. Structure and Dynamics of RNA Repeat Expansions That Cause Huntington's Disease and Myotonic Dystrophy Type 1. Biochemistry 2017; 56:3463-3474. [PMID: 28617590 PMCID: PMC5810133 DOI: 10.1021/acs.biochem.7b00252] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RNA repeat expansions cause a host of incurable, genetically defined diseases. The most common class of RNA repeats consists of trinucleotide repeats. These long, repeating transcripts fold into hairpins containing 1 × 1 internal loops that can mediate disease via a variety of mechanism(s) in which RNA is the central player. Two of these disorders are Huntington's disease and myotonic dystrophy type 1, which are caused by r(CAG) and r(CUG) repeats, respectively. We report the structures of two RNA constructs containing three copies of a r(CAG) [r(3×CAG)] or r(CUG) [r(3×CUG)] motif that were modeled with nuclear magnetic resonance spectroscopy and simulated annealing with restrained molecular dynamics. The 1 × 1 internal loops of r(3×CAG) are stabilized by one-hydrogen bond (cis Watson-Crick/Watson-Crick) AA pairs, while those of r(3×CUG) prefer one- or two-hydrogen bond (cis Watson-Crick/Watson-Crick) UU pairs. Assigned chemical shifts for the residues depended on the identity of neighbors or next nearest neighbors. Additional insights into the dynamics of these RNA constructs were gained by molecular dynamics simulations and a discrete path sampling method. Results indicate that the global structures of the RNA are A-form and that the loop regions are dynamic. The results will be useful for understanding the dynamic trajectory of these RNA repeats but also may aid in the development of therapeutics.
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Affiliation(s)
- Jonathan L. Chen
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Damian M. VanEtten
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, New York 14063, United States
| | - Matthew A. Fountain
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, New York 14063, United States
| | - Ilyas Yildirim
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
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6
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Welty R, Hall KB. Nucleobases Undergo Dynamic Rearrangements during RNA Tertiary Folding. J Mol Biol 2016; 428:4490-4502. [PMID: 27693721 DOI: 10.1016/j.jmb.2016.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/31/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023]
Abstract
The tertiary structure of the GTPase center (GAC) of 23S ribosomal RNA (rRNA) as seen in cocrystals is extremely compact. It is stabilized by long-range hydrogen bonds and nucleobase stacking and by a triloop that forms within its three-way junction. Its folding pathway from secondary structure to tertiary structure has not been previously observed, but it was shown to require Mg2+ ions in equilibrium experiments. The fluorescent nucleotide 2-aminopurine was substituted at selected sites within the 60-nt GAC. Fluorescence intensity changes upon addition of MgCl2 were monitored over a time-course from 1ms to 100s as the RNA folds. The folding pathway is revealed here to be hierarchical through several intermediates. Observation of the nucleobases during folding provides a new perspective on the process and the pathway, revealing the dynamics of nucleobase conformational exchange during the folding transitions.
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Affiliation(s)
- Robb Welty
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Kathleen B Hall
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
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7
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Abstract
The 60-nt GTPase center (GAC) of 23S rRNA has a phylogenetically conserved secondary structure with two hairpin loops and a 3-way junction. It folds into an intricate tertiary structure upon addition of Mg(2+) ions, which is stabilized by the L11 protein in cocrystal structures. Here, we monitor the kinetics of its tertiary folding and Mg(2+)-dependent intermediate states by observing selected nucleobases that contribute specific interactions to the GAC tertiary structure in the cocrystals. The fluorescent nucleobase 2-aminopurine replaced three individual adenines, two of which make long-range stacking interactions and one that also forms hydrogen bonds. Each site reveals a unique response to Mg(2+) addition and temperature, reflecting its environmental change from secondary to tertiary structure. Stopped-flow fluorescence experiments revealed that kinetics of tertiary structure formation upon addition of MgCl2 are also site specific, with local conformational changes occurring from 5 ms to 4s and with global folding from 1 to 5s. Site-specific substitution with (15)N-nucleobases allowed observation of stable hydrogen bond formation by NMR experiments. Equilibrium titration experiments indicate that a stable folding intermediate is present at stoichiometric concentrations of Mg(2+) and suggest that there are two initial sites of Mg(2+) ion association.
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8
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Zhong Z, Soh LH, Lim MH, Chen G. A U⋅U Pair-to-U⋅C Pair Mutation-Induced RNA Native Structure Destabilisation and Stretching-Force-Induced RNA Misfolding. Chempluschem 2015; 80:1267-1278. [PMID: 31973291 DOI: 10.1002/cplu.201500144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 04/21/2015] [Indexed: 12/21/2022]
Abstract
Little is known about how a non-Watson-Crick pair affects the RNA folding dynamics. We studied the effects of a U⋅U-to-U⋅C pair mutation on the folding of a hairpin in human telomerase RNA. The ensemble thermal melting of the hairpins shows an on-pathway intermediate with the disruption of the internal loop structure containing the U⋅U/U⋅C pairs. By using optical tweezers, we applied a stretching force on the terminal ends of the hairpins to probe directly the non-nearest-neighbour effects upon the mutations. The single U⋅U to U⋅C mutations are observed to 1) lower the mechanical unfolding force by approximately 1 picoNewton (pN) per mutation without affecting the unfolding reaction transition-state position (thus suggesting that removing a single hydrogen bond affects the structural dynamics at least two base pairs away), 2) result in more frequent misfolding into a small hairpin at approximately 10 pN and 3) shift the folding reaction transition-state position towards the native hairpin structure and slightly increase the mechanical folding kinetics (thus suggesting that untrapping from the misfolded state is not the rate-limiting step).
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Affiliation(s)
- Zhensheng Zhong
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore), Fax: (+65) 6791-1961
| | - Lai Huat Soh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore), Fax: (+65) 6791-1961
| | - Ming Hui Lim
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore), Fax: (+65) 6791-1961
| | - Gang Chen
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore), Fax: (+65) 6791-1961
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9
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Abstract
RNA dynamics play a fundamental role in many cellular functions. However, there is no general framework to describe these complex processes, which typically consist of many structural maneuvers that occur over timescales ranging from picoseconds to seconds. Here, we classify RNA dynamics into distinct modes representing transitions between basins on a hierarchical free-energy landscape. These transitions include large-scale secondary-structural transitions at >0.1-s timescales, base-pair/tertiary dynamics at microsecond-to-millisecond timescales, stacking dynamics at timescales ranging from nanoseconds to microseconds, and other "jittering" motions at timescales ranging from picoseconds to nanoseconds. We review various modes within these three different tiers, the different mechanisms by which they are used to regulate function, and how they can be coupled together to achieve greater functional complexity.
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10
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Ding N, Chen X, Wu CML, Li H. Adsorption of nucleobase pairs on hexagonal boron nitride sheet: hydrogen bonding versus stacking. Phys Chem Chem Phys 2013; 15:10767-76. [PMID: 23689542 DOI: 10.1039/c3cp50912e] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The adsorption of hydrogen-bonded and stacked nucleobase pairs on the hexagonal boron nitride (h-BN) surface was studied by density functional theory and molecular dynamics methods. Eight types of nucleobase pairs (i.e., GG, AA, TT, CC, UU, AT, GC, and AU) were chosen as the adsorbates. The adsorption configurations, interaction energies, and electronic properties of the nucleobase pair on the h-BN surface were obtained and compared. The density of states analysis result shows that both the hydrogen-bonded and stacked nucleobase pairs were physisorbed on h-BN with minimal charge transfer. The hydrogen-bonded base pairs lying on the h-BN surface are significantly more stable than the stacked forms in both the gas and water phase. The molecular dynamics simulation result indicates that h-BN possessed high sensitivity for the nucleobases and the h-BN surface adsorption could revert the base pair interaction from stacking back to hydrogen bonding in aqueous environment. The h-BN surface could immobilize the nucleobases on its surface, which suggests the use of h-BN has good potential in DNA/RNA detection biosensors and self-assembly nanodevices.
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Affiliation(s)
- Ning Ding
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, PR China
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11
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Mustoe AM, Bailor MH, Teixeira RM, Brooks CL, Al-Hashimi HM. New insights into the fundamental role of topological constraints as a determinant of two-way junction conformation. Nucleic Acids Res 2011; 40:892-904. [PMID: 21937512 PMCID: PMC3258142 DOI: 10.1093/nar/gkr751] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Recent studies have shown that topological constraints encoded at the RNA secondary structure level involving basic steric and stereochemical forces can significantly restrict the orientations sampled by helices across two-way RNA junctions. Here, we formulate these topological constraints in greater quantitative detail and use this topological framework to rationalize long-standing but poorly understood observations regarding the basic behavior of RNA two-way junctions. Notably, we show that the asymmetric nature of the A-form helix and the finite length of a bulge provide a physical basis for the experimentally observed directionality and bulge-length amplitude dependence of bulge induced inter-helical bends. We also find that the topologically allowed space can be modulated by variations in sequence, particularly with the addition of non-canonical GU base pairs at the junction, and, surprisingly, by the length of the 5′ and 3′ helices. A survey of two-way RNA junctions in the protein data bank confirms that junction residues have a strong preference to adopt looped-in, non-canonically base-paired conformations, providing a route for extending our bulge-directed framework to internal loop motifs and implying a simplified link between secondary and tertiary structure. Finally, our results uncover a new simple mechanism for coupling junction-induced topological constraints with tertiary interactions.
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Affiliation(s)
- Anthony M Mustoe
- Departments of Chemistry & Biophysics, The University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109-1055, USA
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12
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Kim Y, Leconte AM, Hari Y, Romesberg FE. Stability and Polymerase Recognition of Pyridine Nucleobase Analogues: Role of Minor-Groove H-Bond Acceptors. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200602579] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Kim Y, Leconte AM, Hari Y, Romesberg FE. Stability and Polymerase Recognition of Pyridine Nucleobase Analogues: Role of Minor-Groove H-Bond Acceptors. Angew Chem Int Ed Engl 2006; 45:7809-12. [PMID: 17075934 DOI: 10.1002/anie.200602579] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yoonkyung Kim
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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14
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D'Souza V, Dey A, Habib D, Summers MF. NMR structure of the 101-nucleotide core encapsidation signal of the Moloney murine leukemia virus. J Mol Biol 2004; 337:427-42. [PMID: 15003457 DOI: 10.1016/j.jmb.2004.01.037] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Revised: 01/19/2004] [Accepted: 01/20/2004] [Indexed: 10/26/2022]
Abstract
The full length, positive-strand genome of the Moloney Murine Leukemia Virus contains a "core encapsidation signal" that is essential for efficient genome packaging during virus assembly. We have determined the structure of a 101-nucleotide RNA that contains this signal (called mPsi) using a novel isotope-edited NMR approach. The method is robust and should be generally applicable to larger RNAs. mPsi folds into three stem loops, two of which (SL-C and SL-D) co-stack to form an extended helix. The third stem loop (SL-B) is connected to SL-C by a flexible, four-nucleotide linker. The structure contains five mismatched base-pairs, an unusual C.CG base-triple platform, and a novel "A-minor K-turn," in which unpaired adenosine bases A340 and A341 of a GGAA bulge pack in the minor groove of a proximal stem, and a bulged distal uridine (U319) forms a hydrogen bond with the phosphodiester of A341. Phylogenetic analyses indicate that these essential structural elements are conserved among the murine C-type retroviruses.
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Affiliation(s)
- Victoria D'Souza
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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15
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Leppert J, Urbinati CR, Häfner S, Ohlenschläger O, Swanson MS, Görlach M, Ramachandran R. Identification of NH...N hydrogen bonds by magic angle spinning solid state NMR in a double-stranded RNA associated with myotonic dystrophy. Nucleic Acids Res 2004; 32:1177-83. [PMID: 14973225 PMCID: PMC373415 DOI: 10.1093/nar/gkh288] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
RNA plays a central role in biological processes and exhibits a variety of secondary and tertiary structural features that are often stabilized via hydrogen bonds. The distance between the donor and acceptor nitrogen nuclei involved in NH...N hydrogen bonds in nucleic acid base pairs is typically in the range of 2.6-2.9 A. Here, we show for the first time that such spatial proximity between 15N nitrogen nuclei can be conveniently monitored via magic angle spinning solid state NMR on a uniformly 15N-labelled RNA. The presence of NH.N hydrogen bonds is reflected as cross-peaks between the donor and acceptor nitrogen nuclei in 2D 15N dipolar chemical shift correlation spectra. The RNA selected for this experimental study was a CUG repeat expansion implicated in the neuromuscular disease myotonic dystrophy. The results presented provide direct evidence that the CUG repeat expansion adopts a double-stranded conformation.
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Affiliation(s)
- Jörg Leppert
- Abteilung Molekulare Biophysik/NMR-Spektroskopie, Institut für Molekulare Biotechnologie, 07745 Jena, Germany
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16
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Baumstark T, Ahlquist P. The brome mosaic virus RNA3 intergenic replication enhancer folds to mimic a tRNA TpsiC-stem loop and is modified in vivo. RNA (NEW YORK, N.Y.) 2001; 7:1652-1670. [PMID: 11720293 PMCID: PMC1370206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The genome of brome mosaic virus (BMV), a positive-strand RNA virus in the alphavirus-like superfamily, consists of three capped, messenger-sense RNAs. RNA1 and RNA2 encode viral replication proteins 1a and 2a, respectively. RNA3 encodes the 3a movement protein and the coat protein, which are essential for systemic infection in plants but dispensable for RNA3 replication in plants and yeast. A subset of the 250-base intergenic region (IGR), the replication enhancer (RE), contains all cis-acting signals necessary for a crucial, early template selection step, the 1a-dependent recruitment of RNA3 into replication. One of these signals is a motif matching the conserved box B sequence of RNA polymerase III transcripts. Using chemical modification with CMCT, kethoxal, DMS, DEPC, and lead, we probed the structure of the IGR in short, defined transcripts and in full-length RNA3 in vitro, in yeast extracts, and in whole yeast cells. Our results reveal a stable, unbranched secondary structure that is not dependent on the surrounding ORF sequences or on host factors within the cell. Functional 5' and 3' deletions that defined the minimal RE in earlier deletion studies map to the end of a common helical segment. The box B motif is presented as a hairpin loop of 7 nt closed by G:C base pairs in perfect analogy to the TpsiC-stem loop in tRNA(Asp). An adjacent U-rich internal loop, a short helix, and another pyrimidine-rich loop were significantly protected from base modifications. This same arrangement is conserved between BMV and cucumoviruses CMV, TAV, and PSV. In the BMV box B loop sequence, uridines corresponding to tRNA positions T54 and psi55 were found to be modified in yeast and plants to 5mU and pseudouridine. Together with the aminoacylated viral 3'-end, this is thus the second RNA replication signal within BMV where the virus has evolved a tRNA structural mimicry to a degree that renders it a substrate for classical tRNA modification reactions in vivo.
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Affiliation(s)
- T Baumstark
- Institute for Molecular Virology and Howard Hughes Medical Institute, University of Wisconsin-Madison, 53706, USA
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17
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Lim VI, Curran JF. Analysis of codon:anticodon interactions within the ribosome provides new insights into codon reading and the genetic code structure. RNA (NEW YORK, N.Y.) 2001; 7:942-957. [PMID: 11453067 PMCID: PMC1370147 DOI: 10.1017/s135583820100214x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Although the decoding rules have been largely elucidated, the physical-chemical reasons for the "correctness" of codon:anticodon duplexes have never been clear. In this work, on the basis of the available data, we propose that the correct codon:anticodon duplexes are those whose formation and interaction with the ribosomal decoding center are not accompanied by uncompensated losses of hydrogen and ionic bonds. Other factors such as proofreading, base-base stacking and aminoacyl-tRNA concentration contribute to the efficiency and accuracy of aminoacyl-tRNA selection, and certainly these factors are important; but we suggest that analyses of hydrogen and ionic bonding alone provides a robust first-order approximation of decoding accuracy. Thus our model can simplify predictions about decoding accuracy and error. The model can be refined with data, but is already powerful enough to explain all of the available data on decoding accuracy. Here we predict which duplexes should be considered correct, which duplexes are responsible for virtually all misreading, and we suggest an evolutionary scheme that gave rise to the mixed boxes of the genetic code.
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Affiliation(s)
- V I Lim
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow
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18
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Brandl M, Meyer M, Sühnel J. Water-Mediated Base Pairs in RNA: A Quantum-Chemical Study. J Phys Chem A 2000. [DOI: 10.1021/jp002022d] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- M. Brandl
- Biocomputing Group, Institute of Molecular Biotechnology, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - M. Meyer
- Biocomputing Group, Institute of Molecular Biotechnology, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - J. Sühnel
- Biocomputing Group, Institute of Molecular Biotechnology, Beutenbergstrasse 11, D-07745 Jena, Germany
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19
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Cordier A, Schön A. Cyanelle RNase P: RNA structure analysis and holoenzyme properties of an organellar ribonucleoprotein enzyme. J Mol Biol 1999; 289:9-20. [PMID: 10339401 DOI: 10.1006/jmbi.1999.2762] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cyanelle of the primitive alga Cyanophora paradoxa is the only photosynthetic organelle where the ribonucleoprotein nature of ribonuclease P has been functionally proven. To increase our knowledge about RNA structure and overall composition of this enzyme, we have now determined relevant physical parameters and performed RNA accessibility experiments. Buoyant density and relative molecular mass of cyanelle RNase P were more similar to the eukaryotic (nuclear or mitochondrial) than to the bacterial enzyme type, despite the close phylogenetic relationship between plastids and cyanobacteria. Enzymatic and chemical probing was used to establish the secondary structure of cyanelle RNase P RNA. The results obtained with the naked transcript support the previously proposed, phylogenetically derived structure. Probing of the RNA in the holoenzyme resulted in reduced sensitivity at a large number of positions, indicating that these regions might be located in the interior of the ribonucleoprotein. Protection of the RNA in cyanelle RNase P was more extensive than reported for the Escherichia coli holoenzyme, but similar to the pattern observed in yeast nuclear RNase P. Taken together, these results indicate that the protein contribution in cyanelle RNase P is much larger than in the bacterial enzymes, and that the overall composition of the holoenzyme resembles that found in eukaryotes.
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Affiliation(s)
- A Cordier
- Institut für Biochemie, Bayerische Julius-Maximilians-Universität, Biozentrum, Würzburg, 97074, Germany
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20
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Abstract
Thermodynamically predicted secondary structure analysis of the 3'-terminal 305 nucleotides (nt) of the rubella virus (RUB) genome, a region conserved in all RUB defective interfering RNAs, revealed four stem-loop (SL) structures; SL1 and SL2 are both located in the E1 coding region, while SL3 and SL4 are within the 59-nt 3' untranslated region (UTR) preceding the poly(A) tract. SL2 is a structure shown to interact with human calreticulin (CAL), an autoantigen potentially involved in RUB RNA replication and pathogenesis. RNase mapping indicated that SL2 and SL3 are in equilibrium between two conformations, in the second of which the previously proposed CAL binding site in SL2, a U-U bulge, is not formed. Site-directed mutagenesis of the 3' UTR with a RUB infectious clone, Robo302, revealed that most of the 3' UTR is required for viral viability except for the 3'-terminal 5 nt and the poly(A) tract, although poly(A) was rapidly regenerated during subsequent replication. Maintenance of the overall SL3 structure, the 11-nt single-stranded sequence between SL3 and SL4, and the sequences forming SL4 were all important for viral viability. Studies on the interaction between host factors and the 3' UTR showed the formation of three RNA-protein complexes by gel mobility shift assay, and UV-induced cross-linking detected six host protein species, with molecular masses of 120, 80, 66, 55, 48, and 36 kDa, interacting with the 3' UTR. Site-directed mutagenesis of SL2 by nucleotide substitutions showed that maintenance of SL2 stem rather than the U-U bulge was critical in CAL binding since mutants having the U-U bulge base paired had a similar binding activity for CAL as the native structure whereas mutants having the SL2 stem destabilized had much lower binding activity. However, all of these mutations gave rise to viable viruses when introduced into Robo302, indicating that binding of CAL to SL2 is independent of viral viability.
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Affiliation(s)
- M H Chen
- Department of Biology, Georgia State University, Atlanta, Georgia 30303, USA
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21
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Jiang L, Patel DJ. Solution structure of the tobramycin-RNA aptamer complex. NATURE STRUCTURAL BIOLOGY 1998; 5:769-74. [PMID: 9731769 DOI: 10.1038/1804] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have solved the solution structure of the aminoglycoside antibiotic tobramycin complexed with a stem-loop RNA aptamer. The 14 base loop of the RNA aptamer 'zippers up' alongside the attached stem through alignment of four mismatches and one Watson-Crick pair on complex formation. The tobramycin inserts into the deep groove centered about the mismatch pairs and is partially encapsulated between its floor and a looped out guanine base that flaps over the bound antibiotic. Several potential intermolecular hydrogen bonds between the charged NH3 groups of tobramycin and acceptor atoms on base pair edges and backbone phosphates anchor the aminoglycoside antibiotic within its sequence/structure specific RNA binding pocket.
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Affiliation(s)
- L Jiang
- Cellular Biochemistry & Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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22
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Hess WR, Fingerhut C, Schön A. RNase P RNA from Prochlorococcus marinus: contribution of substrate domains to recognition by a cyanobacterial ribozyme. FEBS Lett 1998; 431:138-42. [PMID: 9708890 DOI: 10.1016/s0014-5793(98)00729-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The molecular organisation of the Prochlorococcus marinus rnpB gene and the catalytic activity of the encoded RNA were characterised. Kinetic parameters for several pre-tRNA substrates were comparable to those from other eubacterial RNase P RNAs, although unusually high cation concentrations were required. The CCA-end of pre-tRNAs is essential for efficient turnover despite the lack of the canonical binding motif in P. marinus RNase P RNA. A trnR gene is located only 38 nt upstream the rnpB 5' end on the complementary strand. This arrangement resembles those in the plastids of Cyanophora and Porphyra but not in any other bacterium.
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Affiliation(s)
- W R Hess
- Institut für Biologie, Humboldt-Universität, Berlin, Germany
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23
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Fingerhut C, Schön A. Sequence and functional characterization of RNase P RNA from the chl alb containing cyanobacterium Prochlorothrix hollandica. FEBS Lett 1998; 428:161-4. [PMID: 9654127 DOI: 10.1016/s0014-5793(98)00519-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Only a few complete sequences and very limited functional data are available for the catalytic RNA component of cyanobacterial RNase P. The RNase P RNA from the chl alb containing cyanobacterium Prochlorothrix hollandica belongs to a rarely found structural subtype with an extended P15/16 domain. We have established conditions for optimal in vitro ribozyme activity, and determined the kinetic parameters for cleavage of pre-tRNA(Tyr). Analysis of pre-tRNA mutants revealed that the T-stem sequence only plays a modulating role, whereas the CCA end is essential for efficient product formation.
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MESH Headings
- Base Sequence
- Cloning, Molecular
- Endoribonucleases/chemistry
- Endoribonucleases/metabolism
- Kinetics
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis
- Nucleic Acid Conformation
- Polymerase Chain Reaction
- Prochlorothrix/genetics
- Prochlorothrix/metabolism
- RNA Precursors/chemistry
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA, Bacterial/chemistry
- RNA, Bacterial/metabolism
- RNA, Catalytic/chemistry
- RNA, Catalytic/metabolism
- RNA, Transfer, Tyr/chemistry
- RNA, Transfer, Tyr/genetics
- RNA, Transfer, Tyr/metabolism
- Ribonuclease P
- Sequence Deletion
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Affiliation(s)
- C Fingerhut
- Institut für Biochemie, Bayerische Julius-Maximilians-Universität, Biozentrum, Würzburg, Germany
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24
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Napierała M, Krzyzosiak WJ. CUG repeats present in myotonin kinase RNA form metastable "slippery" hairpins. J Biol Chem 1997; 272:31079-85. [PMID: 9388259 DOI: 10.1074/jbc.272.49.31079] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We show that CUG repeats form "slippery" hairpins in their natural sequence context of the myotonin kinase gene transcript. This novel type of RNA structure is characterized by strong S1 and T1 nuclease and lead cleavages in the terminal loop and by mild lead cleavages in the hairpin stem. The latter effect indicates a relaxed metastable structure of the stem. (CUG)5 repeats do not form any detectable secondary structure, whereas hairpins of increasing stability are formed by (CUG)11, (CUG)21, and (CUG)49. The potential role of the RNA hairpin structure in the pathogenesis of myotonic dystrophy is discussed.
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Affiliation(s)
- M Napierała
- Laboratory of Cancer Genetics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
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25
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Ramos A, Varani G. Structure of the acceptor stem of Escherichia coli tRNA Ala: role of the G3.U70 base pair in synthetase recognition. Nucleic Acids Res 1997; 25:2083-90. [PMID: 9153306 PMCID: PMC146727 DOI: 10.1093/nar/25.11.2083] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The fidelity of translation of the genetic code depends on accurate tRNA aminoacylation by cognate aminoacyl-tRNA synthetases. Thus, each tRNA has specificity not only for codon recognition, but also for amino acid identity; this aminoacylation specificity is referred to as tRNA identity. The primary determinant of the acceptor identity of Escherichia coli tRNAAlais a wobble G3.U70 pair within the acceptor stem. Despite extensive biochemical and genetic data, the mechanism by which the G3.U70 pair marks the acceptor end of tRNAAla for aminoacylation with alanine has not been clarified at the molecular level. The solution structure of a microhelix derived from the tRNAAla acceptor end has been determined at high precision using a very extensive set of experimental constraints (approximately 32 per nt) obtained by heteronuclear multidimensional NMR methods. The tRNAAla acceptor end is overall similar to A-form RNA, but important differences are observed. The G3.U70 wobble pair distorts the conformation of the phosphodiester backbone and presents the functional groups of U70 in an unusual spatial location. The discriminator base A73 has extensive stacking overlap with G1 within the G1.C72 base pair at the end of the double helical stem and the -CCA end is significantly less ordered than the rest of the molecule.
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Affiliation(s)
- A Ramos
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK
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26
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Ramos A, Gubser CC, Varani G. Recent solution structures of RNA and its complexes with drugs, peptides and proteins. Curr Opin Struct Biol 1997; 7:317-23. [PMID: 9204272 DOI: 10.1016/s0959-440x(97)80046-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The past two years have seen remarkable progress in the study of RNA structure: the predicted era of RNA structural biology has arrived. Crystallographic structures of the hammerhead ribozyme and of a large subunit of a group I self-splicing intron have begun to reveal the structural basis of RNA enzymatic activity. A remarkable number of structures of small RNAs and of complexes with drugs, peptides and one protein domain have been determined by NMR.
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Affiliation(s)
- A Ramos
- MRC Laboratory of Molecular Biology, Cambridge, UK
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27
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Schuster P, Stadler PF, Renner A. RNA structures and folding: from conventional to new issues in structure predictions. Curr Opin Struct Biol 1997; 7:229-35. [PMID: 9094330 DOI: 10.1016/s0959-440x(97)80030-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Prediction and modeling of RNA structures has become an indispensable tool of biological research disciplines. Currently, reliable predictions require massive input of experimental data. Structure-forming elements are conventional base pairs, as well as a rapidly increasing repertoire of novel structural motifs. New developments extend structural analysis beyond the one-sequence/one-structure paradigm and allow questions that are relevant to molecular evolution to be answered.
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Affiliation(s)
- P Schuster
- Institut für Theoretische Chemie und Strahlenchemie, Universität Wien, Währingerstrabetae 17, A-1090, Wien, Austria.
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28
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Lim VI. Analysis of interactions between the codon-anticodon duplexes within the ribosome: their role in translation. J Mol Biol 1997; 266:877-90. [PMID: 9086267 DOI: 10.1006/jmbi.1996.0802] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Computer graphics simulation of interactions between the codon-anticodon duplexes formed by normal elongator tRNAs at the ribosomal A, P and E-sites (the AP and PE interduplex interactions) was made. This demonstrated that only the correct duplexes at the A-site are compatible with the AP interduplex interaction. The selection of synonymous codons and anticodon wobble bases, together with the AP interduplex interaction, prevents frameshifting. In the absence of this interaction the efficiency of the selection falls off sharply. This suggests that the AP interduplex interaction should be retained during translocation and in the post-translocation state, i.e. the PE interduplex interaction that is identical with that of AP should exist to avoid frameshifting. In such a model the P-site duplex provides an indirect linkage between the A and E-site duplexes. The indirect linkage prohibits the simultaneous existence of the A and E-site duplexes. The wobble pairs of the P and E-site duplexes can affect the rate of the A-site occupation via the AP interduplex interaction and the AE interduplex indirect linkage. It is demonstrated that frameshifting can occur from the AP or PE codon-anticodon complex destabilization caused, for example, by small mobility of the wobble pairs, misreading of the codon, unmodified adenine and guanine at tRNA positions 34 (wobble) and 37, respectively. The results obtained can be subjected to direct experimental tests.
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Affiliation(s)
- V I Lim
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region
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29
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Jiang L, Suri AK, Fiala R, Patel DJ. Saccharide-RNA recognition in an aminoglycoside antibiotic-RNA aptamer complex. CHEMISTRY & BIOLOGY 1997; 4:35-50. [PMID: 9070426 DOI: 10.1016/s1074-5521(97)90235-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Aminoglycoside antibiotics are known to target ribosomal, retroviral and catalytic RNAs with high affinity and specificity. Recently, in vitro selection experiments have identified RNA aptamers that bind to aminoglycoside antibiotics with nanomolar affinity and stringent specificity, allowing discrimination between closely related family members. There has, to date, been limited structural information on the molecular basis of such saccharide-RNA recognition. RESULTS We describe a solution-structure determination of the tobramycin-RNA aptamer complex, obtained using NMR and molecular dynamics. The structure gives insight into the molecular features associated with saccharide-RNA recognition. Tobramycin adopts a defined alignment and binds to the RNA major groove centered about a stem-loop junction site. A portion of the bound tobramycin is encapsulated between the floor of the major groove and a looped-out cytosine residue that forms a flap over the binding site in the complex. CONCLUSIONS The emergence of antibiotic-resistant pathogens and their impact on human health continues to be a major concern in the medical community. Rational modification of existing antibiotics aimed at improving their efficacy requires a molecular view of their receptor-binding sites. We have provided such a molecular view for a member of the aminoglycoside antibiotic family that targets RNA.
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Affiliation(s)
- L Jiang
- Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, new York, NY 10021, USA
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