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Ruszkowska A, Zheng YY, Mao S, Ruszkowski M, Sheng J. Structural Insights Into the 5′UG/3′GU Wobble Tandem in Complex With Ba2+ Cation. Front Mol Biosci 2022; 8:762786. [PMID: 35096964 PMCID: PMC8793689 DOI: 10.3389/fmolb.2021.762786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 11/24/2021] [Indexed: 11/25/2022] Open
Abstract
G•U wobble base pair frequently occurs in RNA structures. The unique chemical, thermodynamic, and structural properties of the G•U pair are widely exploited in RNA biology. In several RNA molecules, the G•U pair plays key roles in folding, ribozyme catalysis, and interactions with proteins. G•U may occur as a single pair or in tandem motifs with different geometries, electrostatics, and thermodynamics, further extending its biological functions. The metal binding affinity, which is essential for RNA folding, catalysis, and other interactions, differs with respect to the tandem motif type due to the different electrostatic potentials of the major grooves. In this work, we present the crystal structure of an RNA 8-mer duplex r[UCGUGCGA]2, providing detailed structural insights into the tandem motif I (5′UG/3′GU) complexed with Ba2+ cation. We compare the electrostatic potential of the presented motif I major groove with previously published structures of tandem motifs I, II (5′GU/3′UG), and III (5′GG/3′UU). A local patch of a strongly negative electrostatic potential in the major groove of the presented structure forms the metal binding site with the contributions of three oxygen atoms from the tandem. These results give us a better understanding of the G•U tandem motif I as a divalent metal binder, a feature essential for RNA functions.
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Affiliation(s)
| | - Ya Ying Zheng
- Department of Chemistry, The RNA Institute, University at Albany, State University of New York, Albany, NY, United States
| | - Song Mao
- Department of Chemistry, The RNA Institute, University at Albany, State University of New York, Albany, NY, United States
| | - Milosz Ruszkowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Jia Sheng
- Department of Chemistry, The RNA Institute, University at Albany, State University of New York, Albany, NY, United States
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2
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Sharma IM, Rappé MC, Addepalli B, Grabow WW, Zhuang Z, Abeysirigunawardena SC, Limbach PA, Jaeger L, Woodson SA. A metastable rRNA junction essential for bacterial 30S biogenesis. Nucleic Acids Res 2019; 46:5182-5194. [PMID: 29850893 PMCID: PMC6007441 DOI: 10.1093/nar/gky120] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/13/2018] [Indexed: 12/26/2022] Open
Abstract
Tertiary sequence motifs encode interactions between RNA helices that create the three-dimensional structures of ribosomal subunits. A Right Angle motif at the junction between 16S helices 5 and 6 (J5/6) is universally conserved amongst small subunit rRNAs and forms a stable right angle in minimal RNAs. J5/6 does not form a right angle in the mature ribosome, suggesting that this motif encodes a metastable structure needed for ribosome biogenesis. In this study, J5/6 mutations block 30S ribosome assembly and 16S maturation in Escherichia coli. Folding assays and in-cell X-ray footprinting showed that J5/6 mutations favor an assembly intermediate of the 16S 5' domain and prevent formation of the central pseudoknot. Quantitative mass spectrometry revealed that mutant pre-30S ribosomes lack protein uS12 and are depleted in proteins uS5 and uS2. Together, these results show that impaired folding of the J5/6 right angle prevents the establishment of inter-domain interactions, resulting in global collapse of the 30S structure observed in electron micrographs of mutant pre-30S ribosomes. We propose that the J5/6 motif is part of a spine of RNA helices that switch conformation at distinct stages of assembly, linking peripheral domains with the 30S active site to ensure the integrity of 30S biogenesis.
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Affiliation(s)
- Indra Mani Sharma
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Mollie C Rappé
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Balasubrahmanyam Addepalli
- Department of Chemistry, Rieveschl Laboratories for Mass Spectrometry, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Wade W Grabow
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
| | - Zhuoyun Zhuang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
| | | | - Patrick A Limbach
- Department of Chemistry, Rieveschl Laboratories for Mass Spectrometry, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Luc Jaeger
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
| | - Sarah A Woodson
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
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3
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Hosseini M, Roy P, Sissler M, Zirbel CL, Westhof E, Leontis N. How to fold and protect mitochondrial ribosomal RNA with fewer guanines. Nucleic Acids Res 2019; 46:10946-10968. [PMID: 30215760 PMCID: PMC6237812 DOI: 10.1093/nar/gky762] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 09/06/2018] [Indexed: 01/25/2023] Open
Abstract
Mammalian mitochondrial ribosomes evolved from bacterial ribosomes by reduction of ribosomal RNAs, increase of ribosomal protein content, and loss of guanine nucleotides. Guanine is the base most sensitive to oxidative damage. By systematically comparing high-quality, small ribosomal subunit RNA sequence alignments and solved 3D ribosome structures from mammalian mitochondria and bacteria, we deduce rules for folding a complex RNA with the remaining guanines shielded from solvent. Almost all conserved guanines in both bacterial and mammalian mitochondrial ribosomal RNA form guanine-specific, local or long-range, RNA–RNA or RNA–protein interactions. Many solvent-exposed guanines conserved in bacteria are replaced in mammalian mitochondria by bases less sensitive to oxidation. New guanines, conserved only in the mitochondrial alignment, are strategically positioned at solvent inaccessible sites to stabilize the ribosomal RNA structure. New mitochondrial proteins substitute for truncated RNA helices, maintain mutual spatial orientations of helices, compensate for lost RNA–RNA interactions, reduce solvent accessibility of bases, and replace guanines conserved in bacteria by forming specific amino acid–RNA interactions.
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Affiliation(s)
- Maryam Hosseini
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Poorna Roy
- Center for RNA Biomedicine, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Marie Sissler
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg France
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403, USA
| | - Eric Westhof
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg France
| | - Neocles Leontis
- Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA
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4
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Abstract
Wobble GU pairs (or GoU) occur frequently within double‐stranded RNA helices interspersed within the standard G═C and A─U Watson‐Crick pairs. However, other types of GoU pairs interacting on their Watson‐Crick edges have been observed. The structural and functional roles of such alternative GoU pairs are surprisingly diverse and reflect the various pairings G and U can form by exploiting all the subtleties of their electronic configurations. Here, the structural characteristics of the GoU pairs are updated following the recent crystallographic structures of functional ribosomal complexes and the development in our understanding of ribosomal translation.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Marat Yusupov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
| | - Gulnara Yusupova
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
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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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6
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Abstract
RNA secondary structure diagrams familiar to molecular biologists summarize at a glance the folding of RNA chains to form Watson–Crick paired double helices. However, they can be misleading: First of all, they imply that the nucleotides in loops and linker segments, which can amount to 35% to 50% of a structured RNA, do not significantly interact with other nucleotides. Secondly, they give the impression that RNA molecules are loosely organized in three-dimensional (3D) space. In fact, structured RNAs are compactly folded as a result of numerous long-range, sequence-specific interactions, many of which involve loop or linker nucleotides. Here, we provide an introduction for students and researchers of RNA on the types, prevalence, and sequence variations of inter-nucleotide interactions that structure and stabilize RNA 3D motifs and architectures, using Escherichia coli (E. coli) 16S ribosomal RNA as a concrete example. The picture that emerges is that almost all nucleotides in structured RNA molecules, including those in nominally single-stranded loop or linker regions, form specific interactions that stabilize functional structures or mediate interactions with other molecules. The small number of noninteracting, ‘looped-out’ nucleotides make it possible for the RNA chain to form sharp turns. Base-pairing is the most specific interaction in RNA as it involves edge-to-edge hydrogen bonding (H-bonding) of the bases. Non-Watson–Crick base pairs are a significant fraction (30% or more) of base pairs in structured RNAs.
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Abstract
RNA molecules are highly modular components that can be used in a variety of contexts for building new metabolic, regulatory and genetic circuits in cells. The majority of synthetic RNA systems to date predominately rely on two-dimensional modularity. However, a better understanding and integration of three-dimensional RNA modularity at structural and functional levels is critical to the development of more complex, functional bio-systems and molecular machines for synthetic biology applications.
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Affiliation(s)
- Wade Grabow
- Department of Chemistry and Biochemistry, Seattle Pacific University3307 Third Avenue West, Seattle, WA 98119USA
| | - Luc Jaeger
- Department of Chemistry and Biochemistry, Bio-Molecular Science and Engineering Program, University of CaliforniaSanta Barbara, CA 93106-9510USA
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8
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Abstract
Non-Watson-Crick pairs like the G·U wobble are frequent in RNA duplexes. Their geometric dissimilarity (nonisostericity) with the Watson-Crick base pairs and among themselves imparts structural variations decisive for biological functions. Through a novel circular representation of base pairs, a simple and general metric scheme for quantification of base-pair nonisostericity, in terms of residual twist and radial difference that can also envisage its mechanistic effect, is proposed. The scheme is exemplified by G·U and U·G wobble pairs, and their predicable local effects on helical twist angle are validated by MD simulations. New insights into a possible rationale for contextual occurrence of G·U and other non-WC pairs, as well as the influence of a G·U pair on other non-Watson-Crick pair neighborhood and RNA-protein interactions are obtained from analysis of crystal structure data. A few instances of RNA-protein interactions along the major groove are documented in addition to the well-recognized interaction of the G·U pair along the minor groove. The nonisostericity-mediated influence of wobble pairs for facilitating helical packing through long-range interactions in ribosomal RNAs is also reviewed.
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Kondo J, Dock-Bregeon AC, Willkomm DK, Hartmann RK, Westhof E. Structure of an A-form RNA duplex obtained by degradation of 6S RNA in a crystallization droplet. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:634-9. [PMID: 23722840 PMCID: PMC3668581 DOI: 10.1107/s1744309113013018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/13/2013] [Indexed: 12/29/2022]
Abstract
In the course of a crystallographic study of a 132 nt variant of Aquifex aeolicus 6S RNA, a crystal structure of an A-form RNA duplex containing 12 base pairs was solved at a resolution of 2.6 Å. In fact, the RNA duplex is part of the 6S RNA and was obtained by accidental but precise degradation of the 6S RNA in a crystallization droplet. 6S RNA degradation was confirmed by microscopic observation of crystals and gel electrophoresis of crystallization droplets. The RNA oligomers obtained form regular A-form duplexes containing three GoU wobble-type base pairs, one of which engages in intermolecular contacts through a ribose-zipper motif at the crystal-packing interface.
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Affiliation(s)
- Jiro Kondo
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan.
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10
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Abstract
Transient or long-term DNA self-assembly participates in essential genetic functions. The present review focuses on tight DNA-DNA interactions that have recently been found to play important roles in both controlling DNA higher-order structures and their topology. Due to their chirality, double helices are tightly packed into stable right-handed crossovers. Simple packing rules that are imposed by DNA geometry and sequence dictate the overall architecture of higher order DNA structures. Close DNA-DNA interactions also provide the missing link between local interactions and DNA topology, thus explaining how type II DNA topoisomerases may sense locally the global topology. Finally this paper proposes that through its influence on DNA self-assembled structures, DNA chirality played a critical role during the early steps of evolution.
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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 Interdiscip Rev 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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Grabow WW, Zhuang Z, Swank ZN, Shea JE, Jaeger L. The right angle (RA) motif: a prevalent ribosomal RNA structural pattern found in group I introns. J Mol Biol 2012; 424:54-67. [PMID: 22999957 DOI: 10.1016/j.jmb.2012.09.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/11/2012] [Accepted: 09/12/2012] [Indexed: 12/16/2022]
Abstract
The right angle (RA) motif, previously identified in the ribosome and used as a structural module for nano-construction, is a recurrent structural motif of 13 nucleotides that establishes a 90° bend between two adjacent helices. Comparative sequence analysis was used to explore the sequence space of the RA motif within ribosomal RNAs in order to define its canonical sequence space signature. We investigated the sequence constraints associated with the RA signature using several artificial self-assembly systems. Thermodynamic and topological investigations of sequence variants associated with the RA motif in both minimal and expanded structural contexts reveal that the presence of a helix at the 3' end of the RA motif increases the thermodynamic stability and rigidity of the resulting three-helix junction domain. A search for the RA in naturally occurring RNAs as well as its experimental characterization led to the identification of the RA in groups IC1 and ID intron ribozymes, where it is suggested to play an integral role in stabilizing peripheral structural domains. The present study exemplifies the need of empirical analysis of RNA structural motifs for facilitating the rational design and structure prediction of RNAs.
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Affiliation(s)
- Wade W Grabow
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
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13
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Mooers BHM, Singh A. The crystal structure of an oligo(U):pre-mRNA duplex from a trypanosome RNA editing substrate. RNA 2011; 17:1870-1883. [PMID: 21878548 PMCID: PMC3185919 DOI: 10.1261/rna.2880311] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 07/30/2011] [Indexed: 05/31/2023]
Abstract
Guide RNAs bind antiparallel to their target pre-mRNAs to form editing substrates in reaction cycles that insert or delete uridylates (Us) in most mitochondrial transcripts of trypanosomes. The 5' end of each guide RNA has an anchor sequence that binds to the pre-mRNA by base-pair complementarity. The template sequence in the middle of the guide RNA directs the editing reactions. The 3' ends of most guide RNAs have ∼15 contiguous Us that bind to the purine-rich unedited pre-mRNA upstream of the editing site. The resulting U-helix is rich in G·U wobble base pairs. To gain insights into the structure of the U-helix, we crystallized 8 bp of the U-helix in one editing substrate for the A6 mRNA of Trypanosoma brucei. The fragment provides three samples of the 5'-AGA-3'/5'-UUU-3' base-pair triple. The fusion of two identical U-helices head-to-head promoted crystallization. We obtained X-ray diffraction data with a resolution limit of 1.37 Å. The U-helix had low and high twist angles before and after each G·U wobble base pair; this variation was partly due to shearing of the wobble base pairs as revealed in comparisons with a crystal structure of a 16-nt RNA with all Watson-Crick base pairs. Both crystal structures had wider major grooves at the junction between the poly(U) and polypurine tracts. This junction mimics the junction between the template helix and the U-helix in RNA-editing substrates and may be a site of major groove invasion by RNA editing proteins.
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Affiliation(s)
- Blaine H M Mooers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104-5419, USA.
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14
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Abstract
Type II topoisomerases are ubiquitous enzymes that control the topology and higher order structures of DNA. Type IIA enzymes have the remarkable property to sense locally the global DNA topology. Although many theoretical models have been proposed, the molecular mechanism of chiral discrimination is still unclear. While experimental studies have established that topoisomerases IIA discriminate topology on the basis of crossover geometry, a recent single-molecule experiment has shown that the enzyme has a different processivity on supercoiled DNA of opposite sign. Understanding how cross-over geometry influences enzyme processivity is, therefore, the key to elucidate the mechanism of chiral discrimination. Analysing this question from the DNA side reveals first, that the different stability of chiral DNA cross-overs provides a way to locally sense the global DNA topology. Second, it shows that these enzymes have evolved to recognize the G- and T-segments stably assembled into a right-handed cross-over. Third, it demonstrates how binding right-handed cross-overs across their large angle imposes a different topological link between the topoIIA rings and the plectonemes of opposite sign thus directly affecting the enzyme freedom of motion and processivity. In bridging geometry and kinetic data, this study brings a simple solution for type IIA topoisomerase chiral discrimination.
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Affiliation(s)
- Youri Timsit
- Information Génomique et Structurale, CNRS - UPR2589, Institut de Microbiologie de la Méditerranée, Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
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15
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Erion TV, Strobel SA. Identification of a tertiary interaction important for cooperative ligand binding by the glycine riboswitch. RNA 2011; 17:74-84. [PMID: 21098652 PMCID: PMC3004068 DOI: 10.1261/rna.2271511] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 10/27/2010] [Indexed: 05/21/2023]
Abstract
The glycine riboswitch has a tandem dual aptamer configuration, where each aptamer is a separate ligand-binding domain, but the aptamers function together to bind glycine cooperatively. We sought to understand the molecular basis of glycine riboswitch cooperativity by comparing sites of tertiary contacts in a series of cooperative and noncooperative glycine riboswitch mutants using hydroxyl radical footprinting, in-line probing, and native gel-shift studies. The results illustrate the importance of a direct or indirect interaction between the P3b hairpin of aptamer 2 and the P1 helix of aptamer 1 in cooperative glycine binding. Furthermore, our data support a model in which glycine binding is sequential; where the binding of glycine to the second aptamer allows tertiary interactions to be made that facilitate binding of a second glycine molecule to the first aptamer. These results provide insight into cooperative ligand binding in RNA macromolecules.
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Affiliation(s)
- Thanh V Erion
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA
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16
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Šponer J, Šponer JE, Petrov AI, Leontis NB. Quantum chemical studies of nucleic acids: can we construct a bridge to the RNA structural biology and bioinformatics communities? J Phys Chem B 2010; 114:15723-41. [PMID: 21049899 DOI: 10.1021/jp104361m] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this feature article, we provide a side-by-side introduction for two research fields: quantum chemical calculations of molecular interaction in nucleic acids and RNA structural bioinformatics. Our main aim is to demonstrate that these research areas, while largely separated in contemporary literature, have substantial potential to complement each other that could significantly contribute to our understanding of the exciting world of nucleic acids. We identify research questions amenable to the combined application of modern ab initio methods and bioinformatics analysis of experimental structures while also assessing the limitations of these approaches. The ultimate aim is to attain valuable physicochemical insights regarding the nature of the fundamental molecular interactions and how they shape RNA structures, dynamics, function, and evolution.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265 Brno, Czech Republic.
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17
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Abstract
To understand how the nucleotide sequence of ribosomal RNA determines its tertiary structure, we developed a new approach for identification of those features of rRNA sequence that are responsible for formation of different short- and long-range interactions. The approach is based on the co-analysis of several examples of a particular recurrent RNA motif. For different cases of the motif, we design combinatorial gene libraries in which equivalent nucleotide positions are randomized. Through in vivo expression of the designed libraries we select those variants that provide for functional ribosomes. Then, analysis of the nucleotide sequences of the selected clones would allow us to determine the sequence constraints imposed on each case of the motif. The constraints shared by all cases are interpreted as providing for the integrity of the motif, while those ones specific for individual cases would enable the motif to fit into the particular structural context. Here we demonstrate the validity of this approach for three examples of the so-called along-groove packing motif found in different parts of ribosomal RNA.
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Affiliation(s)
- Matthieu G Gagnon
- Département de Biochimie, Université de Montréal, Montréal, CP 6128, Succursale Centre-Ville, QC H3C 3J7, Canada
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18
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Abstract
Here, we present a new recurrent RNA arrangement, the so-called adenosine wedge (A-wedge), which is found in three places of the ribosomal RNA in both ribosomal subunits. The arrangement has a hierarchical structure, consisting of elements previously described as recurrent motifs, namely, the along-groove packing motif, the A-minor and the hook-turn. Within the A-wedge, these elements are involved in different types of cause-effect relationships, providing together for the particular tertiary structure of the motif.
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Affiliation(s)
- Matthieu G Gagnon
- Departement de Biochimie, Universite de Montreal, Montreal, Quebec H3C 3J7, Canada
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19
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Abstract
The growing number of high-resolution crystal structures of large RNA molecules provides much information for understanding the principles of structural organization of these complex molecules. Several in-depth analyses of nucleobase-centered RNA structural motifs and backbone conformations have been published based on this information, including a systematic classification of base pairs by Leontis and Westhof. However, hydrogen bonds involving sugar-phosphate backbone atoms of RNA have not been analyzed systematically until recently, although such hydrogen bonds appear to be common both in local and tertiary interactions. Here we review some backbone structural motifs discussed in the literature and analyze a set of eight high-resolution multi-domain RNA structures. The analyzed RNAs are highly structured: among 5372 nucleotides in this set, 89% are involved in at least one "long-range" RNA-RNA hydrogen bond, i.e., hydrogen bonds between atoms in the same residue or sequential residues are ignored. These long-range hydrogen bonds frequently use backbone atoms as hydrogen bond acceptors, i.e., OP1, OP2, O2', O3', O4', or O5', or as a donor (2'OH). A surprisingly large number of such hydrogen bonds are found, considering that neither single-stranded nor double-stranded regions will contain such hydrogen bonds unless additional interactions with other residues exist. Among 8327 long-range hydrogen bonds found in this set of structures, 2811, or about one-third, are hydrogen bonds entailing RNA backbone atoms; they involve 39% of all nucleotides in the structures. The majority of them (2111) are hydrogen bonds entailing ribose hydroxyl groups, which can be used either as a donor or an acceptor; they constitute 25% of all hydrogen bonds and involve 31% of all nucleotides. The phosphate oxygens OP1 or OP2 are used as hydrogen bond acceptors in 12% of all nucleotides, and the ribose ring oxygen O4' and phosphodiester oxygens O3' and O5' are used in 4%, 4%, and 1% of all nucleotides, respectively. Distributions of geometric parameters and some examples of such hydrogen bonds are presented in this report. A novel motif involving backbone hydrogen bonds, the ribose-phosphate zipper, is also identified.
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Affiliation(s)
- Nikolai B Ulyanov
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158-2517, USA
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20
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Laing C, Jung S, Iqbal A, Schlick T. Tertiary motifs revealed in analyses of higher-order RNA junctions. J Mol Biol 2009; 393:67-82. [PMID: 19660472 DOI: 10.1016/j.jmb.2009.07.089] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/29/2009] [Accepted: 07/29/2009] [Indexed: 12/22/2022]
Abstract
RNA junctions are secondary-structure elements formed when three or more helices come together. They are present in diverse RNA molecules with various fundamental functions in the cell. To better understand the intricate architecture of three-dimensional (3D) RNAs, we analyze currently solved 3D RNA junctions in terms of base-pair interactions and 3D configurations. First, we study base-pair interaction diagrams for solved RNA junctions with 5 to 10 helices and discuss common features. Second, we compare these higher-order junctions to those containing 3 or 4 helices and identify global motif patterns such as coaxial stacking and parallel and perpendicular helical configurations. These analyses show that higher-order junctions organize their helical components in parallel and helical configurations similar to lower-order junctions. Their sub-junctions also resemble local helical configurations found in three- and four-way junctions and are stabilized by similar long-range interaction preferences such as A-minor interactions. Furthermore, loop regions within junctions are high in adenine but low in cytosine, and in agreement with previous studies, we suggest that coaxial stacking between helices likely forms when the common single-stranded loop is small in size; however, other factors such as stacking interactions involving noncanonical base pairs and proteins can greatly determine or disrupt coaxial stacking. Finally, we introduce the ribo-base interactions: when combined with the along-groove packing motif, these ribo-base interactions form novel motifs involved in perpendicular helix-helix interactions. Overall, these analyses suggest recurrent tertiary motifs that stabilize junction architecture, pack helices, and help form helical configurations that occur as sub-elements of larger junction networks. The frequent occurrence of similar helical motifs suggest nature's finite and perhaps limited repertoire of RNA helical conformation preferences. More generally, studies of RNA junctions and tertiary building blocks can ultimately help in the difficult task of RNA 3D structure prediction.
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Affiliation(s)
- Christian Laing
- Department of Chemistry, New York University, 251 Mercer Street, New York, NY 10012, USA
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21
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Laing C, Schlick T. Analysis of four-way junctions in RNA structures. J Mol Biol 2009; 390:547-59. [PMID: 19445952 DOI: 10.1016/j.jmb.2009.04.084] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/21/2009] [Accepted: 04/30/2009] [Indexed: 11/24/2022]
Abstract
RNA secondary structures can be divided into helical regions composed of canonical Watson-Crick and related base pairs, as well as single-stranded regions such as hairpin loops, internal loops, and junctions. These elements function as building blocks in the design of diverse RNA molecules with various fundamental functions in the cell. To better understand the intricate architecture of three-dimensional (3D) RNAs, we analyze existing RNA four-way junctions in terms of base-pair interactions and 3D configurations. Specifically, we identify nine broad junction families according to coaxial stacking patterns and helical configurations. We find that helices within junctions tend to arrange in roughly parallel and perpendicular patterns and stabilize their conformations using common tertiary motifs such as coaxial stacking, loop-helix interaction, and helix packing interaction. Our analysis also reveals a number of highly conserved base-pair interaction patterns and novel tertiary motifs such as A-minor-coaxial stacking combinations and sarcin/ricin motif variants. Such analyses of RNA building blocks can ultimately help in the difficult task of RNA 3D structure prediction.
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22
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Abstract
The structural information encoding specific conformations of natural RNAs can be implemented within artificial RNA sequences to control both three-dimensional (3D) shape and self-assembling interfaces for nanotechnology and synthetic biology applications. We have identified three natural RNA motifs known to direct helical topology into approximately 90 degrees bends: a five-way tRNA junction, a three-way junction, and a two-helix bend. These three motifs, embedded within rationally designed RNAs (tectoRNA), were chosen for generating square-shaped tetrameric RNA nanoparticles. The ability of each motif to direct the formation of supramolecular assemblies was compared by both native gel assays and atomic force microscopy. While there are multiple structural solutions for building square-shaped RNA particles, differences in the thermodynamics and molecular dynamics of the 90 degrees motif can lead to different biophysical behaviors for the resulting supramolecular complexes. We demonstrate via structural assembly programming how the different 90 degrees motifs can preferentially direct the formation of either 2D or 3D assemblies.
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Affiliation(s)
- Isil Severcan
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Cody Geary
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Erik Verzemnieks
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Arkadiusz Chworos
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Luc Jaeger
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
- To whom correspondence should be addressed: Phone: 805-893-3628; Fax: 805-893-4120; Email;
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Šponer J, Zgarbová M, Jurečka P, Riley KE, Šponer JE, Hobza P. Reference Quantum Chemical Calculations on RNA Base Pairs Directly Involving the 2′-OH Group of Ribose. J Chem Theory Comput 2009; 5:1166-79. [DOI: 10.1021/ct800547k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Marie Zgarbová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Petr Jurečka
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Kevin E. Riley
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Judit E. Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
| | - Pavel Hobza
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Department of Physical Chemistry, Palacky University, tr. Svobody 26, 771 46 Olomouc, Czech Republic, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center of Biomolecules and Complex Molecular Systems, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic, Department of Chemistry, P.O. Box 23346, University of Puerto Rico, Rio Piedras, Puerto
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24
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Abstract
Stable RNAs are modular and hierarchical 3D architectures taking advantage of recurrent structural motifs to form extensive non-covalent tertiary interactions. Sequence and atomic structure analysis has revealed a novel submotif involving a minimal set of five nucleotides, termed the UA_handle motif (5'XU/AN(n)X3'). It consists of a U:A Watson-Crick: Hoogsteen trans base pair stacked over a classic Watson-Crick base pair, and a bulge of one or more nucleotides that can act as a handle for making different types of long-range interactions. This motif is one of the most versatile building blocks identified in stable RNAs. It enters into the composition of numerous recurrent motifs of greater structural complexity such as the T-loop, the 11-nt receptor, the UAA/GAN and the G-ribo motifs. Several structural principles pertaining to RNA motifs are derived from our analysis. A limited set of basic submotifs can account for the formation of most structural motifs uncovered in ribosomal and stable RNAs. Structural motifs can act as structural scaffoldings and be functionally and topologically equivalent despite sequence and structural differences. The sequence network resulting from the structural relationships shared by these RNA motifs can be used as a proto-language for assisting prediction and rational design of RNA tertiary structures.
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Affiliation(s)
- Luc Jaeger
- Chemistry and Biochemistry Department, University of California, Santa Barbara, CA 93106-9510, USA.
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Nasalean L, Stombaugh J, Zirbel CL, Leontis NB. RNA 3D Structural Motifs: Definition, Identification, Annotation, and Database Searching. Non-Protein Coding RNAs 2008. [DOI: 10.1007/978-3-540-70840-7_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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26
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Abstract
Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG … AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied ‘11nt’ GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC … GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA–RNA interactions are proposed.
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Affiliation(s)
- Cody Geary
- Department of Chemistry and Biochemistry, Biomolecular Science and Engineering Program, University of California at Santa Barbara, Santa Barbara, CA 93106-9510, USA
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Sponer JE, Réblova K, Mokdad A, Sychrovský V, Leszczynski J, Sponer J. Leading RNA tertiary interactions: structures, energies, and water insertion of A-minor and P-interactions. A quantum chemical view. J Phys Chem B 2007; 111:9153-64. [PMID: 17602515 DOI: 10.1021/jp0704261] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Complex molecular shapes of ribosomal RNA molecules are stabilized by recurrent types of tertiary interactions involving highly specific and conserved non-Watson-Crick base pairs, triplets, and quartets. We analyzed the intrinsic structure and stability of the P-motif and the four basic types of A-minor interactions (types I, II, III, and 0), which represent the most prominent RNA tertiary interaction patterns refined in the course of evolution. In the studied interactions, the electron correlation component of the stabilization usually exceeds the Hartree-Fock (HF) term, leading to a strikingly different balance of forces as compared to standard base pairing stabilized primarily by the HF term. In other words, the A-minor and P-interactions are considerably more influenced by the dispersion energy as compared to canonical base pairs, which makes them particularly suitable to zip the folded RNA structures that are substantially hydrated even in their interior. Continuum solvent COSMO calculations confirm that the stability of the canonical GC base pair is affected (reduced) by the continuum solvent screening considerably more than the stability of the A-minor interaction. Among the studied systems, the strong A-minor II and weak A-minor III interactions require water molecules to stabilize the experimental geometry. Gas-phase optimization of the canonical A-minor II A/CG triplet without water results in a geometry that is clearly inconsistent with the RNA structure. The gas-phase structure of the P-interaction and the most stable A-minor I interaction nicely agrees with the geometries occurring in the ribosome. A-minor I can also adopt an alternative water-mediated substate rather often observed in X-ray and molecular dynamics studies. The A-minor I water bridge, however, does not appear to stabilize the tertiary contact, and its role is to provide structural flexibility to this binding pattern within the context of the RNA structure. Interestingly, the insertion of a polar water molecule in the A-minor I A/CG tertiary contact occurring in the A/C tertiary pair is stabilized primarily by the HF (electrostatic) interaction energy, while the dispersion-controlled A/G contact remains firmly bound. Thus, the intrinsic balance of forces as revealed by quantum mechanics (QM) calculations nicely correlates with many behavioral aspects of the studied interactions inside RNA. The comparison of interaction energies computed using quantum chemistry and an AMBER force field reveals that common molecular mechanics calculations perform rather well, except that the strength of the P-interaction is modestly overestimated. We also briefly discuss the non-negligible methodological differences when evaluating simple base-base nucleic acids base pairs and the complex RNA tertiary base pairing patterns using QM procedures.
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Affiliation(s)
- Judit E Sponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic.
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28
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Abstract
The along-groove packing motif is a quasi-reciprocal arrangement of two RNA double helices in which a backbone of each helix is closely packed within the minor groove of the other helix. At the center of the inter-helix contact, a GU base pair in one helix packs against a Watson-Crick base pair in the other helix. Here, based on in vivo selection from a combinatorial gene library of 16 S rRNA and on functional characterization of the selected clones, we demonstrate that the normal ribosome performance requires that helices 3 and 12 be closely packed. In some clones the Watson-Crick and GU base pairs exchange in their positions between the two helices, which affects neither the quality of the helix packing, nor the ribosome function. On the other hand, perturbations in the close packing usually lead to a substantial drop in the ribosome activity. The functionality of the clones containing such perturbations may depend on the presence of particular elements in the vicinity of the area of contact between helices 3 and 12. Such cases do not exist in natural 16 S rRNA, and their selection enriches our knowledge of the constraints imposed on the structure of ribosomal RNA in functional ribosomes.
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Affiliation(s)
- Matthieu G Gagnon
- Département de Biochimie, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
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29
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Jang SB, Hung LW, Jeong MS, Holbrook EL, Chen X, Turner DH, Holbrook SR. The crystal structure at 1.5 angstroms resolution of an RNA octamer duplex containing tandem G.U basepairs. Biophys J 2006; 90:4530-7. [PMID: 16581850 PMCID: PMC1471874 DOI: 10.1529/biophysj.106.081018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The crystal structure of the RNA octamer, 5'-GGCGUGCC-3' has been determined from x-ray diffraction data to 1.5 angstroms resolution. In the crystal, this oligonucleotide forms five self-complementary double-helices in the asymmetric unit. Tandem 5'GU/3'UG basepairs comprise an internal loop in the middle of each duplex. The NMR structure of this octameric RNA sequence is also known, allowing comparison of the variation among the five crystallographic duplexes and the solution structure. The G.U pairs in the five duplexes of the crystal form two direct hydrogen bonds and are stabilized by water molecules that bridge between the base of guanine (N2) and the sugar (O2') of uracil. This contrasts with the NMR structure in which only one direct hydrogen bond is observed for the G.U pairs. The reduced stability of the r(CGUG)2 motif relative to the r(GGUC)2 motif may be explained by the lack of stacking of the uracil bases between the Watson-Crick and G.U pairs as observed in the crystal structure.
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Affiliation(s)
- Se Bok Jang
- Korea Nanobiotechnology Center, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan, Korea.
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30
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Abstract
We present a comprehensive structural, evolutionary and molecular dynamics (MD) study of the G/U wobble basepairs in the ribosome based on high-resolution crystal structures, including the recent Escherichia coli structure. These basepairs are classified according to their tertiary interactions, and sequence conservation at their positions is determined. G/U basepairs participating in tertiary interactions are more conserved than those lacking any interactions. Specific interactions occurring in the G/U shallow groove pocket--like packing interactions (P-interactions) and some phosphate backbone interactions (phosphate-in-pocket interactions)--lead to higher G/U conservation than others. Two salient cases of unique phylogenetic compensation are discovered. First, a P-interaction is conserved through a series of compensatory mutations involving all four participating nucleotides to preserve or restore the G/U in the optimal orientation. Second, a G/U basepair forming a P-interaction and another one forming a phosphate-in-pocket interaction are replaced by GNRA loops that maintain similar tertiary contacts. MD simulations were carried out on eight P-interactions. The specific GU/CG signature of this interaction observed in structure and sequence analysis was rationalized, and can now be used for improving sequence alignments.
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MESH Headings
- Base Pairing
- Base Sequence
- Conserved Sequence
- Crystallography, X-Ray
- Evolution, Molecular
- Guanine/chemistry
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phosphates/chemistry
- RNA, Archaeal/chemistry
- RNA, Bacterial/chemistry
- RNA, Ribosomal/chemistry
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 5S/chemistry
- Ribosomes/chemistry
- Sequence Analysis, RNA
- Uracil/chemistry
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Affiliation(s)
- Ali Mokdad
- To whom correspondence should be addressed. Tel: +1 419 372 2332; Fax: +1 419 372 2024;
| | - Maryna V. Krasovska
- Institute of Biophysics, Academy of Sciences of the Czech RepublicKralovopolska 135, 612 65, Brno, Czech Republic
| | - Jiri Sponer
- Institute of Biophysics, Academy of Sciences of the Czech RepublicKralovopolska 135, 612 65, Brno, Czech Republic
| | - Neocles B. Leontis
- To whom correspondence should be addressed. Tel: +1 419 372 2332; Fax: +1 419 372 2024;
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