1
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Geng A, Roy R, Gu S, Guseva S, Pratihar S, Lee Y, Li L, Kimsey IJ, Wilson MA, Al-Hashimi HM. Insight into the Conformational Ensembles Formed by U-U and T-T Mismatches in RNA and DNA Duplexes From a Structure-based Survey, NMR, and Molecular Dynamics Simulations. J Mol Biol 2025; 437:169197. [PMID: 40345379 DOI: 10.1016/j.jmb.2025.169197] [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: 03/25/2025] [Revised: 05/05/2025] [Accepted: 05/05/2025] [Indexed: 05/11/2025]
Abstract
Nucleic acid base pairs interconvert between alternative conformations on a free energy landscape, and these dynamics play critical roles in recognition, folding, and catalysis. U-U and T-T mismatches can adopt two nearly isoenergetic wobble conformations, distinguished by their relative shearing displacements. Experimental NMR evidence suggests that these conformations dynamically interconvert in RNA motifs containing tandem U-U mismatches. However, whether such motions occur ubiquitously across U-U and T-T mismatches remains unknown, as high-resolution nucleic acid structures typically report only a single conformation. Here, we used NMR spectroscopy, a structure-based survey of the Protein Data Bank, and molecular dynamics (MD) simulations to investigate wobble dynamics in U-U and T-T mismatches when flanked by canonical Watson-Crick base pairs in RNA and DNA duplexes. The structure-based survey revealed that U-U mismatches have propensities to adopt alternative wobble conformations even when controlling for sequence and identified potential intermediates along the wobble transition. Off-resonance R1ρ relaxation dispersion experiments detected no micro- to millisecond dynamics for U-U mismatches in duplex RNA and T-T mismatches in duplex DNA. However, alternative conformer refinement of the electron density in X-ray structures, inter-proton NOEs, carbonyl carbon chemical shifts, an RDC-derived conformational ensemble, and MD simulations indicated that U-U and T-T mismatches exist in a dynamic equilibrium between two wobble conformations, with the minor state exceeding 30% and the transitions occurring on the nanosecond timescale. Our findings suggest that U-U and T-T ubiquitously undergo sub-microsecond wobble motions, contributing to the energetic landscape and dynamic plasticity of nucleic acids, with important implications for processes that generate and act on these mismatches.
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Affiliation(s)
- Ainan Geng
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Rohit Roy
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27701, USA
| | - Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Serafima Guseva
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Supriya Pratihar
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Yeongjoon Lee
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Linshu Li
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Isaac J Kimsey
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Mark A Wilson
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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2
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Ren Y, Lin X, Liao W, Peng X, Deng J, Zhang Z, Zhan J, Zhou Y, Westhof E, Lilley DMJ, Wang J, Huang L. A general strategy for engineering GU base pairs to facilitate RNA crystallization. Nucleic Acids Res 2025; 53:gkae1218. [PMID: 39721592 PMCID: PMC11797044 DOI: 10.1093/nar/gkae1218] [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: 07/05/2024] [Revised: 11/07/2024] [Accepted: 11/26/2024] [Indexed: 12/28/2024] Open
Abstract
X-ray crystallography is a fundamental technique that provides atomic-level insights into RNA structures. However, obtaining crystals of RNA structures diffracting to high resolution is challenging. We introduce a simple strategy to enhance the resolution limit of RNA crystals by the selective substitution of Watson-Crick pairs by GU pairs within RNA sequences. Our approach has successfully yielded high-resolution structures for eight unique RNA crystals. Notably, six instances showed marked resolution enhancement upon GC/AU to GU base pair substitution, with two cases achieving high-resolution structures from initially poor data. In one case, reverting GU to GC base pairs also improved resolution. Our method facilitated the first structural determinations of the Long Interspersed Nuclear Element-1 and Olfactory Receptor family 4 subfamily K member 15 ribozymes, the 2'-deoxyguanosine-III riboswitch and the Broccoli RNA aptamer. The placement of GU base pairs within the first 5' helical stem of any given RNA species, or in one peripheral stem, is shown to be sufficient. These results offer a simple and effective approach for designing sequences or selecting sequences from homologous sequences, for high-resolution RNA structure determination.
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Affiliation(s)
- Yangyi Ren
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Xiaowei Lin
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
- Department of Urology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
- Department of Urology, Dafeng Hospital, Chaoyang District, Shantou 515000, China
| | - Wenjian Liao
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
- Department of Urology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Xuemei Peng
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Jie Deng
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Zhe Zhang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518107, China
| | - Jian Zhan
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518107, China
- Ribopeutic Inc., Guangzhou International Bio Island, Guangzhou 510005, China
| | - Yaoqi Zhou
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518107, China
| | - Eric Westhof
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
- Architecture et Réactivité de l’ARN, Université de Strasbourg, Institut de biologie moléculaire et cellulaire du CNRS, Strasbourg F-67084, France
| | - David M J Lilley
- Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Jia Wang
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China
| | - Lin Huang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
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3
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Timsit Y, Sergeant-Perthuis G, Bennequin D. The role of ribosomal protein networks in ribosome dynamics. Nucleic Acids Res 2025; 53:gkae1308. [PMID: 39788545 PMCID: PMC11711686 DOI: 10.1093/nar/gkae1308] [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: 02/27/2024] [Revised: 12/12/2024] [Accepted: 01/02/2025] [Indexed: 01/12/2025] Open
Abstract
Accurate protein synthesis requires ribosomes to integrate signals from distant functional sites and execute complex dynamics. Despite advances in understanding ribosome structure and function, two key questions remain: how information is transmitted between these distant sites, and how ribosomal movements are synchronized? We recently highlighted the existence of ribosomal protein networks, likely evolved to participate in ribosome signaling. Here, we investigate the relationship between ribosomal protein networks and ribosome dynamics. Our findings show that major motion centers in the bacterial ribosome interact specifically with r-proteins, and that ribosomal RNA exhibits high mobility around each r-protein. This suggests that periodic electrostatic changes in the context of negatively charged residues (Glu and Asp) induce RNA-protein 'distance-approach' cycles, controlling key ribosomal movements during translocation. These charged residues play a critical role in modulating electrostatic repulsion between RNA and proteins, thus coordinating ribosomal dynamics. We propose that r-protein networks synchronize ribosomal dynamics through an 'electrostatic domino' effect, extending the concept of allostery to the regulation of movements within supramolecular assemblies.
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Affiliation(s)
- Youri Timsit
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM110, 163 avenue de Luminy 13288 Marseille, France
- Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara GOSEE, 3 Rue Michel-Ange, 75016 Paris, France
| | - Grégoire Sergeant-Perthuis
- Laboratory of Computational and Quantitative Biology (LCQB), Sorbonne Université, 4 Place Jussieu, 75005 Paris, France
| | - Daniel Bennequin
- Institut de Mathématiques de Jussieu - Paris Rive Gauche (IMJ-PRG), UMR 7586, CNRS, Université Paris Diderot, 8, Pace Aurélie Nemours, 75013 Paris, France
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4
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Srivastava Y, Akinyemi O, Rohe T, Pritchett E, Baker C, Sharma A, Jenkins J, Mathews D, Wedekind J. Two riboswitch classes that share a common ligand-binding fold show major differences in the ability to accommodate mutations. Nucleic Acids Res 2024; 52:13152-13173. [PMID: 39413212 PMCID: PMC11602147 DOI: 10.1093/nar/gkae886] [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: 06/05/2024] [Revised: 09/09/2024] [Accepted: 09/25/2024] [Indexed: 10/18/2024] Open
Abstract
Riboswitches are structured RNAs that sense small molecules to control expression. Prequeuosine1 (preQ1)-sensing riboswitches comprise three classes (I, II and III) that adopt distinct folds. Despite this difference, class II and III riboswitches each use 10 identical nucleotides to bind the preQ1 metabolite. Previous class II studies showed high sensitivity to binding-pocket mutations, which reduced preQ1 affinity and impaired function. Here, we introduced four equivalent mutations into a class III riboswitch, which maintained remarkably tight preQ1 binding. Co-crystal structures of each class III mutant showed compensatory interactions that preserve the fold. Chemical modification analysis revealed localized RNA flexibility changes for each mutant, but molecular dynamics (MD) simulations suggested that each mutation was not overtly destabilizing. Although impaired, class III mutants retained tangible gene-regulatory activity in bacteria compared to equivalent preQ1-II variants; mutations in the preQ1-pocket floor were tolerated better than wall mutations. Principal component analysis of MD trajectories suggested that the most functionally deleterious wall mutation samples different motions compared to wildtype. Overall, the results reveal that formation of compensatory interactions depends on the context of mutations within the overall fold and that functionally deleterious mutations can alter long-range correlated motions that link the riboswitch binding pocket with distal gene-regulatory sequences.
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Affiliation(s)
- Yoshita Srivastava
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
| | - Olayinka Akinyemi
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Department of Physics, University of Rochester, 500 Wilson Blvd, Rochester, NY 14627, USA
| | - Tiana C Rohe
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
| | - Elizabeth M Pritchett
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 704, Rochester, NY 14642, USA
| | - Cameron D Baker
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 704, Rochester, NY 14642, USA
| | - Akshara Sharma
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
| | - Jermaine L Jenkins
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
| | - David H Mathews
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
| | - Joseph E Wedekind
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave MC 712, Rochester, NY 14642, USA
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5
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Kompatscher M, Bartosik K, Erharter K, Plangger R, Juen F, Kreutz C, Micura R, Westhof E, Erlacher M. Contribution of tRNA sequence and modifications to the decoding preferences of E. coli and M. mycoides tRNAGlyUCC for synonymous glycine codons. Nucleic Acids Res 2024; 52:1374-1386. [PMID: 38050960 PMCID: PMC10853795 DOI: 10.1093/nar/gkad1136] [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: 09/13/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 12/07/2023] Open
Abstract
tRNA superwobbling, used by certain bacteria and organelles, is an intriguing decoding concept in which a single tRNA isoacceptor is used to decode all synonymous codons of a four-fold degenerate codon box. While Escherichia coli relies on three tRNAGly isoacceptors to decode the four glycine codons (GGN), Mycoplasma mycoides requires only a single tRNAGly. Both organisms express tRNAGly with the anticodon UCC, which are remarkably similar in sequence but different in their decoding ability. By systematically introducing mutations and altering the number and type of tRNA modifications using chemically synthesized tRNAs, we elucidated the contribution of individual nucleotides and chemical groups to decoding by the E. coli and M. mycoides tRNAGly. The tRNA sequence was identified as the key factor for superwobbling, revealing the T-arm sequence as a novel pivotal element. In addition, the presence of tRNA modifications, although not essential for providing superwobbling, was shown to delicately fine-tune and balance the decoding of synonymous codons. This emphasizes that the tRNA sequence and its modifications together form an intricate system of high complexity that is indispensable for accurate and efficient decoding.
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Affiliation(s)
- Maria Kompatscher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Karolina Bartosik
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Kevin Erharter
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Raphael Plangger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Fabian Sebastian Juen
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, CNRS UPR 9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Matthias D Erlacher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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6
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Krahn N, Zhang J, Melnikov SV, Tharp JM, Villa A, Patel A, Howard R, Gabir H, Patel T, Stetefeld J, Puglisi J, Söll D. tRNA shape is an identity element for an archaeal pyrrolysyl-tRNA synthetase from the human gut. Nucleic Acids Res 2024; 52:513-524. [PMID: 38100361 PMCID: PMC10810272 DOI: 10.1093/nar/gkad1188] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023] Open
Abstract
Protein translation is orchestrated through tRNA aminoacylation and ribosomal elongation. Among the highly conserved structure of tRNAs, they have distinguishing features which promote interaction with their cognate aminoacyl tRNA synthetase (aaRS). These key features are referred to as identity elements. In our study, we investigated the tRNA:aaRS pair that installs the 22nd amino acid, pyrrolysine (tRNAPyl:PylRS). Pyrrolysyl-tRNA synthetases (PylRSs) are naturally encoded in some archaeal and bacterial genomes to acylate tRNAPyl with pyrrolysine. Their large amino acid binding pocket and poor recognition of the tRNA anticodon have been instrumental in incorporating >200 noncanonical amino acids. PylRS enzymes can be divided into three classes based on their genomic structure. Two classes contain both an N-terminal and C-terminal domain, however the third class (ΔpylSn) lacks the N-terminal domain. In this study we explored the tRNA identity elements for a ΔpylSn tRNAPyl from Candidatus Methanomethylophilus alvus which drives the orthogonality seen with its cognate PylRS (MaPylRS). From aminoacylation and translation assays we identified five key elements in ΔpylSn tRNAPyl necessary for MaPylRS activity. The absence of a base (position 8) and a G-U wobble pair (G28:U42) were found to affect the high-resolution structure of the tRNA, while molecular dynamic simulations led us to acknowledge the rigidity imparted from the G-C base pairs (G3:C70 and G5:C68).
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Affiliation(s)
- Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Jingji Zhang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sergey V Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Jeffery M Tharp
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Alessandra Villa
- PDC-Center for High Performance Computing, KTH-Royal Institute of Technology, Stockholm, SE-100 44, Sweden
| | - Armaan Patel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Rebecca J Howard
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, SE-171 65, Sweden
| | - Haben Gabir
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Trushar R Patel
- Department of Chemistry and Biochemistry, Alberta RNA Research and Training Institute, University of Lethbridge, Lethbridge, AB T1K 2E1, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Department of Microbiology, Immunology & Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jörg Stetefeld
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Joseph Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
- Department of Chemistry, Yale University, New Haven, CT 06520, USA
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7
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Ojha M, Vogt J, Das NK, Redmond E, Singh K, Banna HA, Sadat T, Koirala D. Structure of saguaro cactus virus 3' translational enhancer mimics 5' cap for eIF4E binding. Proc Natl Acad Sci U S A 2024; 121:e2313677121. [PMID: 38241435 PMCID: PMC10823258 DOI: 10.1073/pnas.2313677121] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/18/2023] [Indexed: 01/21/2024] Open
Abstract
The genomes of several plant viruses contain RNA structures at their 3' ends called cap-independent translation enhancers (CITEs) that bind the host protein factors such as mRNA 5' cap-binding protein eIF4E for promoting cap-independent genome translation. However, the structural basis of such 5' cap-binding protein recognition by the uncapped RNA remains largely unknown. Here, we have determined the crystal structure of a 3' CITE, panicum mosaic virus-like translation enhancer (PTE) from the saguaro cactus virus (SCV), using a Fab crystallization chaperone. The PTE RNA folds into a three-way junction architecture with a pseudoknot between the purine-rich R domain and pyrimidine-rich Y domain, which organizes the overall structure to protrude out a specific guanine nucleotide, G18, from the R domain that comprises a major interaction site for the eIF4E binding. The superimposable crystal structures of the wild-type, G18A, G18C, and G18U mutants suggest that the PTE scaffold is preorganized with the flipped-out G18 ready to dock into the eIF4E 5' cap-binding pocket. The binding studies with wheat and human eIF4Es using gel electrophoresis and isothermal titration calorimetry, and molecular docking computation for the PTE-eIF4E complex demonstrated that the PTE structure essentially mimics the mRNA 5' cap for eIF4E binding. Such 5' cap mimicry by the uncapped and structured viral RNA highlights how viruses can exploit RNA structures to mimic the host protein-binding partners and bypass the canonical mechanisms for their genome translation, providing opportunities for a better understanding of virus-host interactions and non-canonical translation mechanisms found in many pathogenic RNA viruses.
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Affiliation(s)
- Manju Ojha
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Jeff Vogt
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Naba Krishna Das
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Emily Redmond
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Karndeep Singh
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
- HHMI, University of Maryland Baltimore County, Baltimore, MD21250
| | - Hasan Al Banna
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Tasnia Sadat
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
| | - Deepak Koirala
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD21250
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8
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Borovská I, Vořechovský I, Královičová J. Alu RNA fold links splicing with signal recognition particle proteins. Nucleic Acids Res 2023; 51:8199-8216. [PMID: 37309897 PMCID: PMC10450188 DOI: 10.1093/nar/gkad500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/23/2023] [Accepted: 05/31/2023] [Indexed: 06/14/2023] Open
Abstract
Transcriptomic diversity in primates was considerably expanded by exonizations of intronic Alu elements. To better understand their cellular mechanisms we have used structure-based mutagenesis coupled with functional and proteomic assays to study the impact of successive primate mutations and their combinations on inclusion of a sense-oriented AluJ exon in the human F8 gene. We show that the splicing outcome was better predicted by consecutive RNA conformation changes than by computationally derived splicing regulatory motifs. We also demonstrate an involvement of SRP9/14 (signal recognition particle) heterodimer in splicing regulation of Alu-derived exons. Nucleotide substitutions that accumulated during primate evolution relaxed the conserved left-arm AluJ structure including helix H1 and reduced the capacity of SRP9/14 to stabilize the closed Alu conformation. RNA secondary structure-constrained mutations that promoted open Y-shaped conformations of the Alu made the Alu exon inclusion reliant on DHX9. Finally, we identified additional SRP9/14 sensitive Alu exons and predicted their functional roles in the cell. Together, these results provide unique insights into architectural elements required for sense Alu exonization, identify conserved pre-mRNA structures involved in exon selection and point to a possible chaperone activity of SRP9/14 outside the mammalian signal recognition particle.
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Affiliation(s)
- Ivana Borovská
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava 840 05, Slovak Republic
| | - Igor Vořechovský
- Faculty of Medicine, University of Southampton, HDH, MP808, Southampton SO16 6YD, United Kingdom
| | - Jana Královičová
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava 840 05, Slovak Republic
- Institute of Zoology, Slovak Academy of Sciences, Bratislava 845 06, Slovak Republic
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9
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Westhof E, Watson ZL, Zirbel CL, Cate JHD. Anionic G•U pairs in bacterial ribosomal rRNAs. RNA (NEW YORK, N.Y.) 2023; 29:1069-1076. [PMID: 37068913 DOI: 10.1261/rna.079583.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/05/2023] [Indexed: 06/18/2023]
Abstract
Wobble GU pairs (or G•U) occur frequently within double-stranded RNA helices interspersed between standard G=C and A-U Watson-Crick pairs. Another type of G•U pair interacting via their Watson-Crick edges has been observed in the A site of ribosome structures between a modified U34 in the tRNA anticodon triplet and G + 3 in the mRNA. In such pairs, the electronic structure of the U is changed with a negative charge on N3(U), resulting in two H-bonds between N1(G)…O4(U) and N2(G)…N3(U). Here, we report that such pairs occur in other highly conserved positions in ribosomal RNAs of bacteria in the absence of U modification. An anionic cis Watson-Crick G•G pair is also observed and well conserved in the small subunit. These pairs are observed in tightly folded regions.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de biologie moléculaire et cellulaire du CNRS, F-67084 Strasbourg, France
| | - Zoe L Watson
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, USA
| | - Craig L Zirbel
- Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, Ohio 43403, USA
| | - Jamie H D Cate
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, California 94720, USA
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10
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Souza TML, Pinho VD, Setim CF, Sacramento CQ, Marcon R, Fintelman-Rodrigues N, Chaves OA, Heller M, Temerozo JR, Ferreira AC, Mattos M, Momo PB, Dias SSG, Gesto JSM, Pereira-Dutra F, Viola JPB, Queiroz-Junior CM, Guimarães LC, Chaves IM, Guimarães PPG, Costa VV, Teixeira MM, Bou-Habib DC, Bozza PT, Aguillón AR, Siqueira-Junior J, Macedo-Junior S, Andrade EL, Fadanni GP, Tolouei SEL, Potrich FB, Santos AA, Marques NF, Calixto JB, Rabi JA. Preclinical development of kinetin as a safe error-prone SARS-CoV-2 antiviral able to attenuate virus-induced inflammation. Nat Commun 2023; 14:199. [PMID: 36639383 PMCID: PMC9837764 DOI: 10.1038/s41467-023-35928-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Orally available antivirals against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are necessary because of the continuous circulation of new variants that challenge immunized individuals. Because severe COVID-19 is a virus-triggered immune and inflammatory dysfunction, molecules endowed with both antiviral and anti-inflammatory activity are highly desirable. We identified here that kinetin (MB-905) inhibits the in vitro replication of SARS-CoV-2 in human hepatic and pulmonary cell lines. On infected monocytes, MB-905 reduced virus replication, IL-6 and TNFα levels. MB-905 is converted into its triphosphate nucleotide to inhibit viral RNA synthesis and induce error-prone virus replication. Coinhibition of SARS-CoV-2 exonuclease, a proofreading enzyme that corrects erroneously incorporated nucleotides during viral RNA replication, potentiated the inhibitory effect of MB-905. MB-905 shows good oral absorption, its metabolites are stable, achieving long-lasting plasma and lung concentrations, and this drug is not mutagenic nor cardiotoxic in acute and chronic treatments. SARS-CoV-2-infected hACE-mice and hamsters treated with MB-905 show decreased viral replication, lung necrosis, hemorrhage and inflammation. Because kinetin is clinically investigated for a rare genetic disease at regimens beyond the predicted concentrations of antiviral/anti-inflammatory inhibition, our investigation suggests the opportunity for the rapid clinical development of a new antiviral substance for the treatment of COVID-19.
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Affiliation(s)
- Thiago Moreno L Souza
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil.
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil.
| | - Vagner D Pinho
- Microbiológica Química e Farmacêutica, Doutor Nicanor, 238 Inhaúma, Rio de Janeiro, RJ, Brazil
| | - Cristina F Setim
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Carolina Q Sacramento
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Rodrigo Marcon
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Natalia Fintelman-Rodrigues
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Otavio A Chaves
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Melina Heller
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Jairo R Temerozo
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Neuroimmunomodulation (INCT/NIM), Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, RJ, Brazil
- Laboratório de Pesquisa sobre o Timo, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, RJ, Brazil
| | - André C Ferreira
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
- Universidade Iguaçu, Nova Iguaçu, RJ, Brazil
| | - Mayara Mattos
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Patrícia B Momo
- Microbiológica Química e Farmacêutica, Doutor Nicanor, 238 Inhaúma, Rio de Janeiro, RJ, Brazil
| | - Suelen S G Dias
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
| | - João S M Gesto
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
- National Institute for Science and Technology on Innovation in Diseases of Neglected Populations (INCT/IDPN), Center for Technological Development in Health (CDTS), Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Filipe Pereira-Dutra
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
| | - João P B Viola
- Program of Immunology and Tumor Biology, Brazilian National Cancer Institute (INCA), Rua André Cavalcanti 37, 5th floor, Centro, Rio de Janeiro, Brazil
| | - Celso Martins Queiroz-Junior
- Centro de Pesquisa e Desenvolvimento de Fármacos, Instituto de Ciências Biológicas, (ICB), Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Brazil
| | - Lays Cordeiro Guimarães
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ian Meira Chaves
- Centro de Pesquisa e Desenvolvimento de Fármacos, Instituto de Ciências Biológicas, (ICB), Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Brazil
| | - Pedro Pires Goulart Guimarães
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vivian Vasconcelos Costa
- Centro de Pesquisa e Desenvolvimento de Fármacos, Instituto de Ciências Biológicas, (ICB), Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Brazil
| | - Mauro Martins Teixeira
- Centro de Pesquisa e Desenvolvimento de Fármacos, Instituto de Ciências Biológicas, (ICB), Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Brazil
| | - Dumith Chequer Bou-Habib
- National Institute for Science and Technology on Neuroimmunomodulation (INCT/NIM), Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, RJ, Brazil
- Laboratório de Pesquisa sobre o Timo, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Patrícia T Bozza
- Laboratório de Imunofarmacologia, Oswaldo Cruz Institute, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ, Brazil
| | - Anderson R Aguillón
- Microbiológica Química e Farmacêutica, Doutor Nicanor, 238 Inhaúma, Rio de Janeiro, RJ, Brazil
| | - Jarbas Siqueira-Junior
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Sergio Macedo-Junior
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Edineia L Andrade
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Guilherme P Fadanni
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Sara E L Tolouei
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Francine B Potrich
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Adara A Santos
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - Naiani F Marques
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil
| | - João B Calixto
- Centro de Inovação e Ensaios Pré-clínicos and National Institute for Science and Technology on Innovation in Medicines and Identification of New Therapeutics Targets (INCT-INOVAMED). Avenida Luiz Boiteux Piazza, 1302 Cachoeira do Bom Jesus, 88056-000, Florianópolis, SC, Brazil.
| | - Jaime A Rabi
- Microbiológica Química e Farmacêutica, Doutor Nicanor, 238 Inhaúma, Rio de Janeiro, RJ, Brazil.
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11
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L’ARNm et ses modifications chez les eucaryotes*. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2022. [DOI: 10.1016/j.banm.2022.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Kiliszek A, Pluta M, Bejger M, Rypniewski W. Structure and thermodynamics of a UGG motif interacting with Ba2+ and other metal ions: accommodating changes in the RNA structure and the presence of a G(syn)-G(syn) pair. RNA (NEW YORK, N.Y.) 2022; 29:rna.079414.122. [PMID: 36319090 PMCID: PMC9808570 DOI: 10.1261/rna.079414.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
The self-complementary triplet 5'UGG3'/5'UGG3' is a particular structural motif containing noncanonical G-G pair and two U·G wobble pairs. It constitutes a specific structural and electrostatic environment attracting metal ions, particularly Ba2+ ions. Crystallographic research has shown that two Ba2+ cations are located in the major groove of the helix and interact directly with the UGG triplet. A comparison with the unliganded structure has revealed global changes in the RNA structure in the presence of metal ions, whereas thermodynamic measurements have shown increased stability. Moreover, in the structure with Ba2+, an unusual noncanonical G(syn)-G(syn) pair is observed instead of the common G(anti)-G(syn). We further elucidate the metal binding properties of the UGG/UGG triplet by performing crystallographic and thermodynamic studies using DSC and UV melting with other metal ions. The results explain the preferences of the UGG sequence for Ba2+ cations and point to possible applications of this metal-binding propensity.
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13
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Yarus M. A crescendo of competent coding (c3) contains the Standard Genetic Code. RNA (NEW YORK, N.Y.) 2022; 28:1337-1347. [PMID: 35868841 PMCID: PMC9479743 DOI: 10.1261/rna.079275.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
The Standard Genetic Code (SGC) can arise by fusion of partial codes evolved in different individuals, perhaps for differing prior tasks. Such code fragments can be unified into an SGC after later evolution of accurate third-position Crick wobble. Late wobble advent fills in the coding table, leaving only later development of translational initiation and termination to reach the SGC in separated domains of life. This code fusion mechanism is computationally implemented here. Late Crick wobble after C3 fusion (c3-lCw) is tested for its ability to evolve the SGC. Compared with previously studied isolated coding tables, or with increasing numbers of parallel, but nonfusing codes, c3-lCw reaches the SGC sooner, is successful in a smaller population, and presents accurate and complete codes more frequently. Notably, a long crescendo of SGC-like codes is exposed for selection of superior translation. c3-lCw also effectively suppresses varied disordered assignments, thus converging on a unified code. Such merged codes closely approach the SGC, making its selection plausible. For example: Under routine conditions, ≈1 of 22 c3-lCw environments evolves codes with ≥20 assignments and ≤3 differences from the SGC, notably including codes identical to the Standard Genetic Code.
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Affiliation(s)
- Michael Yarus
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA
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14
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Hassler HB, Probert B, Moore C, Lawson E, Jackson RW, Russell BT, Richards VP. Phylogenies of the 16S rRNA gene and its hypervariable regions lack concordance with core genome phylogenies. MICROBIOME 2022; 10:104. [PMID: 35799218 PMCID: PMC9264627 DOI: 10.1186/s40168-022-01295-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 05/23/2022] [Indexed: 05/02/2023]
Abstract
BACKGROUND The 16S rRNA gene is used extensively in bacterial phylogenetics, in species delineation, and now widely in microbiome studies. However, the gene suffers from intragenomic heterogeneity, and reports of recombination and an unreliable phylogenetic signal are accumulating. Here, we compare core gene phylogenies to phylogenies constructed using core gene concatenations to estimate the strength of signal for the 16S rRNA gene, its hypervariable regions, and all core genes at the intra- and inter-genus levels. Specifically, we perform four intra-genus analyses (Clostridium, n = 65; Legionella, n = 47; Staphylococcus, n = 36; and Campylobacter, n = 17) and one inter-genus analysis [41 core genera of the human gut microbiome (31 families, 17 orders, and 12 classes), n = 82]. RESULTS At both taxonomic levels, the 16S rRNA gene was recombinant and subject to horizontal gene transfer. At the intra-genus level, the gene showed one of the lowest levels of concordance with the core genome phylogeny (50.7% average). Concordance for hypervariable regions was lower still, with entropy masking providing little to no benefit. A major factor influencing concordance was SNP count, which showed a positive logarithmic association. Using this relationship, we determined that 690 ± 110 SNPs were required for 80% concordance (average 16S rRNA gene SNP count was 254). We also found a wide range in 16S-23S-5S rRNA operon copy number among genomes (1-27). At the inter-genus level, concordance for the whole 16S rRNA gene was markedly higher (73.8% - 10th out of 49 loci); however, the most concordant hypervariable regions (V4, V3-V4, and V1-V2) ranked in the third quartile (62.5 to 60.0%). CONCLUSIONS Ramifications of a poor phylogenetic performance for the 16S rRNA gene are far reaching. For example, in addition to incorrect species/strain delineation and phylogenetic inference, it has the potential to confound community diversity metrics if phylogenetic information is incorporated - for example, with popular approaches such as Faith's phylogenetic diversity and UniFrac. Our results highlight the problematic nature of these approaches and their use (along with entropy masking) is discouraged. Lastly, the wide range in 16S rRNA gene copy number among genomes also has a strong potential to confound diversity metrics. Video Abstract.
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Affiliation(s)
- Hayley B. Hassler
- Department of Biological Sciences, College of Science, Clemson University, Clemson, SC 29634 USA
| | - Brett Probert
- Department of Biological Sciences, College of Science, Clemson University, Clemson, SC 29634 USA
| | - Carson Moore
- Department of Biological Sciences, College of Science, Clemson University, Clemson, SC 29634 USA
| | - Elizabeth Lawson
- Department of Biological Sciences, College of Science, Clemson University, Clemson, SC 29634 USA
| | | | - Brook T. Russell
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, SC 29634 USA
| | - Vincent P. Richards
- Department of Biological Sciences, College of Science, Clemson University, Clemson, SC 29634 USA
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15
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Zuber J, Schroeder SJ, Sun H, Turner DH, Mathews DH. Nearest neighbor rules for RNA helix folding thermodynamics: improved end effects. Nucleic Acids Res 2022; 50:5251-5262. [PMID: 35524574 PMCID: PMC9122537 DOI: 10.1093/nar/gkac261] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/29/2022] [Accepted: 04/08/2022] [Indexed: 12/26/2022] Open
Abstract
Nearest neighbor parameters for estimating the folding stability of RNA secondary structures are in widespread use. For helices, current parameters penalize terminal AU base pairs relative to terminal GC base pairs. We curated an expanded database of helix stabilities determined by optical melting experiments. Analysis of the updated database shows that terminal penalties depend on the sequence identity of the adjacent penultimate base pair. New nearest neighbor parameters that include this additional sequence dependence accurately predict the measured values of 271 helices in an updated database with a correlation coefficient of 0.982. This refined understanding of helix ends facilitates fitting terms for base pair stacks with GU pairs. Prior parameter sets treated 5′GGUC3′ paired to 3′CUGG5′ separately from other 5′GU3′/3′UG5′ stacks. The improved understanding of helix end stability, however, makes the separate treatment unnecessary. Introduction of the additional terms was tested with three optical melting experiments. The average absolute difference between measured and predicted free energy changes at 37°C for these three duplexes containing terminal adjacent AU and GU pairs improved from 1.38 to 0.27 kcal/mol. This confirms the need for the additional sequence dependence in the model.
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Affiliation(s)
- Jeffrey Zuber
- Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA
| | - Susan J Schroeder
- Department of Chemistry and Biochemistry, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Hongying Sun
- Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Douglas H Turner
- Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.,Department of Chemistry, University of Rochester, Rochester, NY 14627, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.,Department of Biostatistics & Computational Biology, University of Rochester, Rochester, NY 14642, USA
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16
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Westhof E, Thornlow B, Chan PP, Lowe TM. Eukaryotic tRNA sequences present conserved and amino acid-specific structural signatures. Nucleic Acids Res 2022; 50:4100-4112. [PMID: 35380696 PMCID: PMC9023262 DOI: 10.1093/nar/gkac222] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/16/2022] [Accepted: 03/22/2022] [Indexed: 11/18/2022] Open
Abstract
Metazoan organisms have many tRNA genes responsible for decoding amino acids. The set of all tRNA genes can be grouped in sets of common amino acids and isoacceptor tRNAs that are aminoacylated by corresponding aminoacyl-tRNA synthetases. Analysis of tRNA alignments shows that, despite the high number of tRNA genes, specific tRNA sequence motifs are highly conserved across multicellular eukaryotes. The conservation often extends throughout the isoacceptors and isodecoders with, in some cases, two sets of conserved isodecoders. This study is focused on non-Watson–Crick base pairs in the helical stems, especially GoU pairs. Each of the four helical stems may contain one or more conserved GoU pairs. Some are amino acid specific and could represent identity elements for the cognate aminoacyl tRNA synthetases. Other GoU pairs are found in more than a single amino acid and could be critical for native folding of the tRNAs. Interestingly, some GoU pairs are anticodon-specific, and others are found in phylogenetically-specific clades. Although the distribution of conservation likely reflects a balance between accommodating isotype-specific functions as well as those shared by all tRNAs essential for ribosomal translation, such conservations may indicate the existence of specialized tRNAs for specific translation targets, cellular conditions, or alternative functions.
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Affiliation(s)
- Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR 9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Bryan Thornlow
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Patricia P Chan
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Todd M Lowe
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA.,UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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17
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Fractional 2'-O-methylation in the ribosomal RNA of Dictyostelium discoideum supports ribosome heterogeneity in Amoebozoa. Sci Rep 2022; 12:1952. [PMID: 35121764 PMCID: PMC8817022 DOI: 10.1038/s41598-022-05447-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/07/2022] [Indexed: 12/02/2022] Open
Abstract
A hallmark of ribosomal RNA (rRNA) are 2′-O-methyl groups that are introduced sequence specifically by box C/D small nucleolar RNAs (snoRNAs) in ribonucleoprotein particles. Most data on this chemical modification and its impact on RNA folding and stability are derived from organisms of the Opisthokonta supergroup. Using bioinformatics and RNA-seq data, we identify 30 novel box C/D snoRNAs in Dictyostelium discoideum, many of which are differentially expressed during the multicellular development of the amoeba. By applying RiboMeth-seq, we find 49 positions in the 17S and 26S rRNA 2′-O-methylated. Several of these nucleotides are substoichiometrically modified, with one displaying dynamic modification levels during development. Using homology-based models for the D. discoideum rRNA secondary structures, we localize many modified nucleotides in the vicinity of the ribosomal A, P and E sites. For most modified positions, a guiding box C/D snoRNA could be identified, allowing to determine idiosyncratic features of the snoRNA/rRNA interactions in the amoeba. Our data from D. discoideum represents the first evidence for ribosome heterogeneity in the Amoebozoa supergroup, allowing to suggest that it is a common feature of all eukaryotes.
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18
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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: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [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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19
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Abstract
Minimally evolved codes are constructed here; these have randomly chosen standard genetic code (SGC) triplets, completed with completely random triplet assignments. Such "genetic codes" have not evolved, but retain SGC qualities. Retained qualities are basic, part of the underpinning of coding. For example, the sensitivity of coding to arbitrary assignments, which must be < ∼10%, is intrinsic. Such sensitivity comes from the elementary combinatorial properties of coding and constrains any SGC evolution hypothesis. Similarly, assignment of last-evolved functions is difficult because of late kinetic phenomena, likely common across codes. Census of minimally evolved code assignments shows that shape and size of wobble domains controls the code's fit into a coding table, strongly shifting accuracy of codon assignments. Access to the SGC therefore requires a plausible pathway to limited randomness, avoiding difficult completion while fitting a highly ordered, degenerate code into a preset three-dimensional space. Three-dimensional late Crick wobble in a genetic code assembled by lateral transfer between early partial codes satisfies these varied, simultaneous requirements. By allowing parallel evolution of SGC domains, this origin can yield shortened evolution to SGC-level order and allow the code to arise in smaller populations. It effectively yields full codes. Less obviously, it unifies previously studied chemical, biochemical, and wobble order in amino acid assignment, including a stereochemical minority of triplet-amino acid associations. Finally, fusion of intermediates into the final SGC is credible, mirroring broadly accepted later cellular evolution.
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20
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An RNA-centric historical narrative around the Protein Data Bank. J Biol Chem 2021; 296:100555. [PMID: 33744291 PMCID: PMC8080527 DOI: 10.1016/j.jbc.2021.100555] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/17/2021] [Accepted: 03/16/2021] [Indexed: 01/06/2023] Open
Abstract
Some of the amazing contributions brought to the scientific community by the Protein Data Bank (PDB) are described. The focus is on nucleic acid structures with a bias toward RNA. The evolution and key roles in science of the PDB and other structural databases for nucleic acids illustrate how small initial ideas can become huge and indispensable resources with the unflinching willingness of scientists to cooperate globally. The progress in the understanding of the molecular interactions driving RNA architectures followed the rapid increase in RNA structures in the PDB. That increase was consecutive to improvements in chemical synthesis and purification of RNA molecules, as well as in biophysical methods for structure determination and computer technology. The RNA modeling efforts from the early beginnings are also described together with their links to the state of structural knowledge and technological development. Structures of RNA and of its assemblies are physical objects, which, together with genomic data, allow us to integrate present-day biological functions and the historical evolution in all living species on earth.
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21
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Auffinger P, Ennifar E, D'Ascenzo L. Deflating the RNA Mg 2+ bubble. Stereochemistry to the rescue! RNA (NEW YORK, N.Y.) 2020; 27:rna.076067.120. [PMID: 33268500 PMCID: PMC7901845 DOI: 10.1261/rna.076067.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 11/20/2020] [Indexed: 05/03/2023]
Abstract
Proper evaluation of the ionic structure of biomolecular systems through X ray and cryo-EM techniques remains challenging but is essential for advancing our understanding of the underlying structure/activity/solvent relationships. However, numerous studies overestimate the number of Mg2+ in deposited structures due to assignment errors finding their origin in improper consideration of stereochemical rules. Herein, to tackle such issues, we re-evaluate the PDBid 6QNR and 6SJ6 models of the ribosome ionic structure. We establish that stereochemical principles need to be carefully pondered when evaluating ion binding features, even when K+ anomalous signals are available as it is the case for the 6QNR PDB entry. For ribosomes, assignment errors can result in misleading conceptions of their solvent structure. For instance, present stereochemical analysis result in a significant decrease of the number of assigned Mg2+ in 6QNR, suggesting that K+ and not Mg2+ is the prevalent ion in the ribosome 1st solvation shell. We stress that the use of proper stereochemical guidelines in combination or not with other identification techniques, such as those pertaining to the detection of transition metals, of some anions and of K+ anomalous signals, is critical for deflating the current Mg2+ bubble witnessed in many ribosome and other RNA structures. We also stress that for the identification of lighter ions such as Mg2+, Na+, …, for which no anomalous signals can be detected, stereochemistry coupled with high resolution structures (<2.4 Å) remain the best currently available option.
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22
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Wolff P, Villette C, Zumsteg J, Heintz D, Antoine L, Chane-Woon-Ming B, Droogmans L, Grosjean H, Westhof E. Comparative patterns of modified nucleotides in individual tRNA species from a mesophilic and two thermophilic archaea. RNA (NEW YORK, N.Y.) 2020; 26:1957-1975. [PMID: 32994183 PMCID: PMC7668247 DOI: 10.1261/rna.077537.120] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 09/09/2020] [Indexed: 05/22/2023]
Abstract
To improve and complete our knowledge of archaeal tRNA modification patterns, we have identified and compared the modification pattern (type and location) in tRNAs of three very different archaeal species, Methanococcus maripaludis (a mesophilic methanogen), Pyrococcus furiosus (a hyperthermophile thermococcale), and Sulfolobus acidocaldarius (an acidophilic thermophilic sulfolobale). Most abundant isoacceptor tRNAs (79 in total) for each of the 20 amino acids were isolated by two-dimensional gel electrophoresis followed by in-gel RNase digestions. The resulting oligonucleotide fragments were separated by nanoLC and their nucleotide content analyzed by mass spectrometry (MS/MS). Analysis of total modified nucleosides obtained from complete digestion of bulk tRNAs was also performed. Distinct base- and/or ribose-methylations, cytidine acetylations, and thiolated pyrimidines were identified, some at new positions in tRNAs. Novel, some tentatively identified, modifications were also found. The least diversified modification landscape is observed in the mesophilic Methanococcus maripaludis and the most complex one in Sulfolobus acidocaldarius Notable observations are the frequent occurrence of ac4C nucleotides in thermophilic archaeal tRNAs, the presence of m7G at positions 1 and 10 in Pyrococcus furiosus tRNAs, and the use of wyosine derivatives at position 37 of tRNAs, especially those decoding U1- and C1-starting codons. These results complete those already obtained by others with sets of archaeal tRNAs from Methanocaldococcus jannaschii and Haloferax volcanii.
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Affiliation(s)
- Philippe Wolff
- Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Claire Villette
- Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Julie Zumsteg
- Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Dimitri Heintz
- Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Laura Antoine
- Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Béatrice Chane-Woon-Ming
- Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
| | - Louis Droogmans
- Laboratoire de Chimie Biologique, Université Libre de Bruxelles, Institut Labiris, B-1070, Belgium
| | - Henri Grosjean
- Laboratoire de Chimie Biologique, Université Libre de Bruxelles, Institut Labiris, B-1070, Belgium
| | - Eric Westhof
- Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, F-67084, Strasbourg, France
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23
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Schäck MA, Jablonski KP, Gräf S, Klassen R, Schaffrath R, Kellner S, Hammann C. Eukaryotic life without tQCUG: the role of Elongator-dependent tRNA modifications in Dictyostelium discoideum. Nucleic Acids Res 2020; 48:7899-7913. [PMID: 32609816 PMCID: PMC7430636 DOI: 10.1093/nar/gkaa560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 12/23/2022] Open
Abstract
In the Elongator-dependent modification pathway, chemical modifications are introduced at the wobble uridines at position 34 in transfer RNAs (tRNAs), which serve to optimize codon translation rates. Here, we show that this three-step modification pathway exists in Dictyostelium discoideum, model of the evolutionary superfamily Amoebozoa. Not only are previously established modifications observable by mass spectrometry in strains with the most conserved genes of each step deleted, but also additional modifications are detected, indicating a certain plasticity of the pathway in the amoeba. Unlike described for yeast, D. discoideum allows for an unconditional deletion of the single tQCUG gene, as long as the Elongator-dependent modification pathway is intact. In gene deletion strains of the modification pathway, protein amounts are significantly reduced as shown by flow cytometry and Western blotting, using strains expressing different glutamine leader constructs fused to GFP. Most dramatic are these effects, when the tQCUG gene is deleted, or Elp3, the catalytic component of the Elongator complex is missing. In addition, Elp3 is the most strongly conserved protein of the modification pathway, as our phylogenetic analysis reveals. The implications of this observation are discussed with respect to the evolutionary age of the components acting in the Elongator-dependent modification pathway.
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Affiliation(s)
- Manfred A Schäck
- Ribogenetics Biochemistry Lab, Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, DE 28759 Bremen, Germany
| | - Kim Philipp Jablonski
- Ribogenetics Biochemistry Lab, Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, DE 28759 Bremen, Germany
| | - Stefan Gräf
- Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Stefanie Kellner
- Department of Chemistry and Pharmacy, Ludwig-Maximilians University Munich, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Christian Hammann
- Ribogenetics Biochemistry Lab, Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, DE 28759 Bremen, Germany
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24
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Rangadurai A, Szymanski ES, Kimsey I, Shi H, Al-Hashimi HM. Probing conformational transitions towards mutagenic Watson-Crick-like G·T mismatches using off-resonance sugar carbon R 1ρ relaxation dispersion. JOURNAL OF BIOMOLECULAR NMR 2020; 74:457-471. [PMID: 32789613 PMCID: PMC7508749 DOI: 10.1007/s10858-020-00337-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 07/13/2020] [Indexed: 05/30/2023]
Abstract
NMR off-resonance R1ρ relaxation dispersion measurements on base carbon and nitrogen nuclei have revealed that wobble G·T/U mismatches in DNA and RNA duplexes exist in dynamic equilibrium with short-lived, low-abundance, and mutagenic Watson-Crick-like conformations. As Watson-Crick-like G·T mismatches have base pairing geometries similar to Watson-Crick base pairs, we hypothesized that they would mimic Watson-Crick base pairs with respect to the sugar-backbone conformation as well. Using off-resonance R1ρ measurements targeting the sugar C3' and C4' nuclei, a structure survey, and molecular dynamics simulations, we show that wobble G·T mismatches adopt sugar-backbone conformations that deviate from the canonical Watson-Crick conformation and that transitions toward tautomeric and anionic Watson-Crick-like G·T mismatches restore the canonical Watson-Crick sugar-backbone. These measurements also reveal kinetic isotope effects for tautomerization in D2O versus H2O, which provide experimental evidence in support of a transition state involving proton transfer. The results provide additional evidence in support of mutagenic Watson-Crick-like G·T mismatches, help rule out alternative inverted wobble conformations in the case of anionic G·T-, and also establish sugar carbons as new non-exchangeable probes of this exchange process.
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Affiliation(s)
- Atul Rangadurai
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Eric S Szymanski
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
- Nymirum, 4324 S. Alston Avenue, Durham, NC, 27713, USA
| | - Isaac Kimsey
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
- Nymirum, 4324 S. Alston Avenue, Durham, NC, 27713, USA
| | - Honglue Shi
- Department of Chemistry, Duke University, Durham, NC, 27710, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Chemistry, Duke University, Durham, NC, 27710, USA.
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25
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C5-Substituted 2-Selenouridines Ensure Efficient Base Pairing with Guanosine; Consequences for Reading the NNG-3' Synonymous mRNA Codons. Int J Mol Sci 2020; 21:ijms21082882. [PMID: 32326096 PMCID: PMC7216251 DOI: 10.3390/ijms21082882] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 12/14/2022] Open
Abstract
5-Substituted 2-selenouridines (R5Se2U) are post-transcriptional modifications present in the first anticodon position of transfer RNA. Their functional role in the regulation of gene expression is elusive. Here, we present efficient syntheses of 5-methylaminomethyl-2-selenouridine (1, mnm5Se2U), 5-carboxymethylaminomethyl-2-selenouridine (2, cmnm5Se2U), and Se2U (3) alongside the crystal structure of the latter nucleoside. By using pH-dependent potentiometric titration, pKa values for the N3H groups of 1–3 were assessed to be significantly lower compared to their 2-thio- and 2-oxo-congeners. At physiological conditions (pH 7.4), Se2-uridines 1 and 2 preferentially adopted the zwitterionic form (ZI, ca. 90%), with the positive charge located at the amino alkyl side chain and the negative charge at the Se2-N3-O4 edge. As shown by density functional theory (DFT) calculations, this ZI form efficiently bound to guanine, forming the so-called “new wobble base pair”, which was accepted by the ribosome architecture. These data suggest that the tRNA anticodons with wobble R5Se2Us may preferentially read the 5′-NNG-3′ synonymous codons, unlike their 2-thio- and 2-oxo-precursors, which preferentially read the 5′-NNA-3′ codons. Thus, the interplay between the levels of U-, S2U- and Se2U-tRNA may have a dominant role in the epitranscriptomic regulation of gene expression via reading of the synonymous 3′-A- and 3′-G-ending codons.
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26
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Cornish-Bowden A, Cárdenas ML. Contrasting theories of life: Historical context, current theories. In search of an ideal theory. Biosystems 2020; 188:104063. [DOI: 10.1016/j.biosystems.2019.104063] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 12/18/2022]
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27
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Antoine L, Wolff P, Westhof E, Romby P, Marzi S. Mapping post-transcriptional modifications in Staphylococcus aureus tRNAs by nanoLC/MSMS. Biochimie 2019; 164:60-69. [PMID: 31295507 DOI: 10.1016/j.biochi.2019.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/03/2019] [Indexed: 02/06/2023]
Abstract
RNA modifications are involved in numerous biological processes. These modifications are constitutive or modulated in response to adaptive processes and can impact RNA base-pairing formation, protein recognition, RNA structure and stability. tRNAs are the most abundantly modified RNA molecules. Analysis of the roles of their modifications in response to stress, environmental changes, and infections caused by pathogens, has fueled new research areas. Nevertheless, the detection of modified nucleotides in RNAs is still a challenging task. We present here a reliable method to identify and localize tRNA modifications, which was applied to the human pathogenic bacteria, Staphyloccocus aureus. The method is based on a separation of tRNA species on a two-dimensional polyacrylamide gel electrophoresis followed by nano liquid chromatography-mass spectrometry. We provided a list of modifications mapped on 25 out of the 40 tRNA species (one isoacceptor for each amino acid). This method can be easily used to monitor the dynamics of tRNA modifications in S. aureus in response to stress adaptation and during infection of the host, a relatively unexplored field.
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Affiliation(s)
- Laura Antoine
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Philippe Wolff
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France; Plateforme Protéomique Strasbourg Esplanade, CNRS, FR1589, F-67000, Strasbourg, France
| | - Eric Westhof
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Pascale Romby
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Stefano Marzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France.
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28
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Westhof E, Yusupov M, Yusupova G. The multiple flavors of GoU pairs in RNA. J Mol Recognit 2019; 32:e2782. [PMID: 31033092 PMCID: PMC6617799 DOI: 10.1002/jmr.2782] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/02/2019] [Accepted: 03/14/2019] [Indexed: 11/10/2022]
Abstract
Wobble GU pairs (or GoU) occur frequently within double‐stranded RNA helices interspersed within the standard G═C and A─U Watson‐Crick pairs. However, other types of GoU pairs interacting on their Watson‐Crick edges have been observed. The structural and functional roles of such alternative GoU pairs are surprisingly diverse and reflect the various pairings G and U can form by exploiting all the subtleties of their electronic configurations. Here, the structural characteristics of the GoU pairs are updated following the recent crystallographic structures of functional ribosomal complexes and the development in our understanding of ribosomal translation.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Marat Yusupov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
| | - Gulnara Yusupova
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
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