1
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Yoon PH, Zhang Z, Loi KJ, Adler BA, Lahiri A, Vohra K, Shi H, Rabelo DB, Trinidad M, Boger RS, Al-Shimary MJ, Doudna JA. Structure-guided discovery of ancestral CRISPR-Cas13 ribonucleases. Science 2024; 385:538-543. [PMID: 39024377 DOI: 10.1126/science.adq0553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 07/02/2024] [Indexed: 07/20/2024]
Abstract
The RNA-guided ribonuclease CRISPR-Cas13 enables adaptive immunity in bacteria and programmable RNA manipulation in heterologous systems. Cas13s share limited sequence similarity, hindering discovery of related or ancestral systems. To address this, we developed an automated structural-search pipeline to identify an ancestral clade of Cas13 (Cas13an) and further trace Cas13 origins to defense-associated ribonucleases. Despite being one-third the size of other Cas13s, Cas13an mediates robust programmable RNA depletion and defense against diverse bacteriophages. However, unlike its larger counterparts, Cas13an uses a single active site for both CRISPR RNA processing and RNA-guided cleavage, revealing that the ancestral nuclease domain has two modes of activity. Discovery of Cas13an deepens our understanding of CRISPR-Cas evolution and expands opportunities for precision RNA editing, showcasing the promise of structure-guided genome mining.
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Affiliation(s)
- Peter H Yoon
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
| | - Zeyuan Zhang
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA
| | - Kenneth J Loi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Benjamin A Adler
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA
| | - Arushi Lahiri
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Kamakshi Vohra
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA
| | - Honglue Shi
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
| | - Daniel Bellieny Rabelo
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA
| | - Marena Trinidad
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
| | - Ron S Boger
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA, USA
| | - Muntathar J Al-Shimary
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA
- Gladstone Institutes, San Francisco, CA, USA
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
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2
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Kehrli J, Husser C, Ryckelynck M. Fluorogenic RNA-Based Biosensors of Small Molecules: Current Developments, Uses, and Perspectives. BIOSENSORS 2024; 14:376. [PMID: 39194605 DOI: 10.3390/bios14080376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/14/2024] [Accepted: 07/19/2024] [Indexed: 08/29/2024]
Abstract
Small molecules are highly relevant targets for detection and quantification. They are also used to diagnose and monitor the progression of disease and infectious processes and track the presence of contaminants. Fluorogenic RNA-based biosensors (FRBs) represent an appealing solution to the problem of detecting these targets. They combine the portability of molecular systems with the sensitivity and multiplexing capacity of fluorescence, as well as the exquisite ligand selectivity of RNA aptamers. In this review, we first present the different sensing and reporting aptamer modules currently available to design an FRB, together with the main methodologies used to discover modules with new specificities. We next introduce and discuss how both modules can be functionally connected prior to exploring the main applications for which FRB have been used. Finally, we conclude by discussing how using alternative nucleotide chemistries may improve FRB properties and further widen their application scope.
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Affiliation(s)
- Janine Kehrli
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Claire Husser
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Michael Ryckelynck
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
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3
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Fernando CM, Breaker RR. Bioinformatic prediction of proteins relevant to functions of the bacterial OLE ribonucleoprotein complex. mSphere 2024; 9:e0015924. [PMID: 38771028 PMCID: PMC11332333 DOI: 10.1128/msphere.00159-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/19/2024] [Indexed: 05/22/2024] Open
Abstract
OLE (ornate, large, extremophilic) RNAs are members of a noncoding RNA class present in many Gram-positive, extremophilic bacteria. The large size, complex structure, and extensive sequence conservation of OLE RNAs are characteristics consistent with the hypothesis that they likely function as ribozymes. The OLE RNA representative from Halalkalibacterium halodurans is known to localize to the phospholipid membrane and requires at least three essential protein partners: OapA, OapB, and OapC. However, the precise biochemical functions of this unusual ribonucleoprotein (RNP) complex remain unknown. Genetic disruption of OLE RNA or its partners revealed that the complex is beneficial under diverse stress conditions. To search for additional links between OLE RNA and other cellular components, we used phylogenetic profiling to identify proteins that are either correlated or anticorrelated with the presence of OLE RNA in various bacterial species. This analysis revealed strong correlations between the essential protein-binding partners of OLE RNA and organisms that carry the ole gene. Similarly, proteins involved in sporulation are correlated, suggesting a potential role for the OLE RNP complex in spore formation. Intriguingly, the Mg2+ transporter MpfA is strongly anticorrelated with OLE RNA. Evidence indicates that MpfA is structurally related to OapA and therefore MpfA may serve as a functional replacement for some contributions otherwise performed by the OLE RNP complex in species that lack this device. Indeed, OLE RNAs might represent an ancient RNA class that enabled primitive organisms to sense and respond to major cellular stresses.IMPORTANCEOLE (ornate, large, extremophilic) RNAs were first reported nearly 20 years ago, and they represent one of the largest and most intricately folded noncoding RNA classes whose biochemical function remains to be established. Other RNAs with similar size, structural complexity, and extent of sequence conservation have proven to catalyze chemical transformations. Therefore, we speculate that OLE RNAs likewise operate as ribozymes and that they might catalyze a fundamental reaction that has persisted since the RNA World era-a time before the emergence of proteins in evolution. To seek additional clues regarding the function of OLE RNA, we undertook a computational effort to identify potential protein components of the OLE ribonucleoprotein (RNP) complex or other proteins that have functional links to this device. This analysis revealed known protein partners and several additional proteins that might be physically or functionally linked to the OLE RNP complex. Finally, we identified a Mg2+ transporter protein, MpfA, that strongly anticorrelates with the OLE RNP complex. This latter result suggests that MpfA might perform at least some functions that are like those carried out by the OLE RNP complex.
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Affiliation(s)
- Chrishan M. Fernando
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Ronald R. Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, USA
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4
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He S, Huang R, Townley J, Kretsch RC, Karagianes TG, Cox DBT, Blair H, Penzar D, Vyaltsev V, Aristova E, Zinkevich A, Bakulin A, Sohn H, Krstevski D, Fukui T, Tatematsu F, Uchida Y, Jang D, Lee JS, Shieh R, Ma T, Martynov E, Shugaev MV, Bukhari HST, Fujikawa K, Onodera K, Henkel C, Ron S, Romano J, Nicol JJ, Nye GP, Wu Y, Choe C, Reade W, Das R. Ribonanza: deep learning of RNA structure through dual crowdsourcing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.24.581671. [PMID: 38464325 PMCID: PMC10925082 DOI: 10.1101/2024.02.24.581671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Prediction of RNA structure from sequence remains an unsolved problem, and progress has been slowed by a paucity of experimental data. Here, we present Ribonanza, a dataset of chemical mapping measurements on two million diverse RNA sequences collected through Eterna and other crowdsourced initiatives. Ribonanza measurements enabled solicitation, training, and prospective evaluation of diverse deep neural networks through a Kaggle challenge, followed by distillation into a single, self-contained model called RibonanzaNet. When fine tuned on auxiliary datasets, RibonanzaNet achieves state-of-the-art performance in modeling experimental sequence dropout, RNA hydrolytic degradation, and RNA secondary structure, with implications for modeling RNA tertiary structure.
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Affiliation(s)
- Shujun He
- Department of Chemical Engineering, Texas A&M University, TX, USA
| | - Rui Huang
- Department of Biochemistry, Stanford CA, USA
| | | | | | | | - David B T Cox
- Department of Biochemistry, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
| | | | - Dmitry Penzar
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Valeriy Vyaltsev
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
| | - Elizaveta Aristova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
| | - Arsenii Zinkevich
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
| | - Artemy Bakulin
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
| | - Hoyeol Sohn
- Department of Chemical Engineering, Texas A&M University, TX, USA
- Department of Biochemistry, Stanford CA, USA
- Eterna Massive Open Laboratory
- Biophysics Program, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
- Department of Mathematics, Stanford CA, USA
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
- GO Inc., Tokyo, Japan
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
- DeltaX, Seoul, Republic of Korea
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
- Vergesense, CA
- DeNA, Tokyo, Japan
- NVIDIA, Tokyo, Japan
- NVIDIA, Munich
- Howard Hughes Medical Institute
- Department of Bioengineering, Stanford CA, USA
- Kaggle, San Francisco CA, USA
| | - Daniel Krstevski
- Department of Chemical Engineering, Texas A&M University, TX, USA
- Department of Biochemistry, Stanford CA, USA
- Eterna Massive Open Laboratory
- Biophysics Program, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
- Department of Mathematics, Stanford CA, USA
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
- GO Inc., Tokyo, Japan
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
- DeltaX, Seoul, Republic of Korea
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
- Vergesense, CA
- DeNA, Tokyo, Japan
- NVIDIA, Tokyo, Japan
- NVIDIA, Munich
- Howard Hughes Medical Institute
- Department of Bioengineering, Stanford CA, USA
- Kaggle, San Francisco CA, USA
| | | | | | | | - Donghoon Jang
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
| | | | - Roger Shieh
- Department of Chemical Engineering, Texas A&M University, TX, USA
- Department of Biochemistry, Stanford CA, USA
- Eterna Massive Open Laboratory
- Biophysics Program, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
- Department of Mathematics, Stanford CA, USA
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
- GO Inc., Tokyo, Japan
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
- DeltaX, Seoul, Republic of Korea
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
- Vergesense, CA
- DeNA, Tokyo, Japan
- NVIDIA, Tokyo, Japan
- NVIDIA, Munich
- Howard Hughes Medical Institute
- Department of Bioengineering, Stanford CA, USA
- Kaggle, San Francisco CA, USA
| | - Tom Ma
- Department of Chemical Engineering, Texas A&M University, TX, USA
- Department of Biochemistry, Stanford CA, USA
- Eterna Massive Open Laboratory
- Biophysics Program, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
- Department of Mathematics, Stanford CA, USA
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
- GO Inc., Tokyo, Japan
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
- DeltaX, Seoul, Republic of Korea
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
- Vergesense, CA
- DeNA, Tokyo, Japan
- NVIDIA, Tokyo, Japan
- NVIDIA, Munich
- Howard Hughes Medical Institute
- Department of Bioengineering, Stanford CA, USA
- Kaggle, San Francisco CA, USA
| | - Eduard Martynov
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
| | - Maxim V Shugaev
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
| | | | | | | | | | - Shlomo Ron
- Department of Chemical Engineering, Texas A&M University, TX, USA
- Department of Biochemistry, Stanford CA, USA
- Eterna Massive Open Laboratory
- Biophysics Program, Stanford CA, USA
- Department of Medicine, Division of Hematology, and Department of Biochemistry, Stanford CA, USA
- Department of Mathematics, Stanford CA, USA
- AIRI, Moscow, Russia
- Vavilov Institute of General Genetics, Moscow 119991, Russia
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Russian Federation
- GO Inc., Tokyo, Japan
- Department of Electrical and Computer Engineering, Inha University, Incheon, Republic of Korea
- DeltaX, Seoul, Republic of Korea
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russian Federation
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904-4745, USA
- Vergesense, CA
- DeNA, Tokyo, Japan
- NVIDIA, Tokyo, Japan
- NVIDIA, Munich
- Howard Hughes Medical Institute
- Department of Bioengineering, Stanford CA, USA
- Kaggle, San Francisco CA, USA
| | - Jonathan Romano
- Eterna Massive Open Laboratory
- Howard Hughes Medical Institute
| | | | - Grace P Nye
- Department of Biochemistry, Stanford CA, USA
| | - Yuan Wu
- Department of Biochemistry, Stanford CA, USA
- Howard Hughes Medical Institute
| | | | | | - Rhiju Das
- Department of Biochemistry, Stanford CA, USA
- Biophysics Program, Stanford CA, USA
- Howard Hughes Medical Institute
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5
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Narunsky A, Higgs GA, Torres BM, Yu D, de Andrade GB, Kavita K, Breaker RR. The discovery of novel noncoding RNAs in 50 bacterial genomes. Nucleic Acids Res 2024; 52:5152-5165. [PMID: 38647067 PMCID: PMC11109978 DOI: 10.1093/nar/gkae248] [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: 10/12/2023] [Revised: 03/20/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024] Open
Abstract
Structured noncoding RNAs (ncRNAs) contribute to many important cellular processes involving chemical catalysis, molecular recognition and gene regulation. Few ncRNA classes are broadly distributed among organisms from all three domains of life, but the list of rarer classes that exhibit surprisingly diverse functions is growing. We previously developed a computational pipeline that enables the near-comprehensive identification of structured ncRNAs expressed from individual bacterial genomes. The regions between protein coding genes are first sorted based on length and the fraction of guanosine and cytidine nucleotides. Long, GC-rich intergenic regions are then examined for sequence and structural similarity to other bacterial genomes. Herein, we describe the implementation of this pipeline on 50 bacterial genomes from varied phyla. More than 4700 candidate intergenic regions with the desired characteristics were identified, which yielded 44 novel riboswitch candidates and numerous other putative ncRNA motifs. Although experimental validation studies have yet to be conducted, this rate of riboswitch candidate discovery is consistent with predictions that many hundreds of novel riboswitch classes remain to be discovered among the bacterial species whose genomes have already been sequenced. Thus, many thousands of additional novel ncRNA classes likely remain to be discovered in the bacterial domain of life.
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Affiliation(s)
- Aya Narunsky
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Gadareth A Higgs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Blake M Torres
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Diane Yu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Gabriel Belem de Andrade
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Kumari Kavita
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06511, USA
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6
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Ren K, Zhou F, Zhang F, Yin M, Zhu Y, Wang S, Chen Y, Huang T, Wu Z, He J, Zhang A, Guo C, Huang Z. Discovery and structural mechanism of DNA endonucleases guided by RAGATH-18-derived RNAs. Cell Res 2024; 34:370-385. [PMID: 38575718 PMCID: PMC11061315 DOI: 10.1038/s41422-024-00952-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/09/2024] [Indexed: 04/06/2024] Open
Abstract
CRISPR-Cas systems and IS200/IS605 transposon-associated TnpBs have been utilized for the development of genome editing technologies. Using bioinformatics analysis and biochemical experiments, here we present a new family of RNA-guided DNA endonucleases. Our bioinformatics analysis initially identifies the stable co-occurrence of conserved RAGATH-18-derived RNAs (reRNAs) and their upstream IS607 TnpBs with an average length of 390 amino acids. IS607 TnpBs form programmable DNases through interaction with reRNAs. We discover the robust dsDNA interference activity of IS607 TnpB systems in bacteria and human cells. Further characterization of the Firmicutes bacteria IS607 TnpB system (ISFba1 TnpB) reveals that its dsDNA cleavage activity is remarkably sensitive to single mismatches between the guide and target sequences in human cells. Our findings demonstrate that a length of 20 nt in the guide sequence of reRNA achieves the highest DNA cleavage activity for ISFba1 TnpB. A cryo-EM structure of the ISFba1 TnpB effector protein bound by its cognate RAGATH-18 motif-containing reRNA and a dsDNA target reveals the mechanisms underlying reRNA recognition by ISFba1 TnpB, reRNA-guided dsDNA targeting, and the sensitivity of the ISFba1 TnpB system to base mismatches between the guide and target DNA. Collectively, this study identifies the IS607 TnpB family of compact and specific RNA-guided DNases with great potential for application in gene editing.
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Affiliation(s)
- Kuan Ren
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Fengxia Zhou
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
- Westlake Center for Genome Editing, Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Fan Zhang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
| | - Mingyu Yin
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yuwei Zhu
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Shouyu Wang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yan Chen
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Tengjin Huang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Zixuan Wu
- Westlake Center for Genome Editing, Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Jiale He
- Westlake Center for Genome Editing, Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Anqi Zhang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Changyou Guo
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Zhiwei Huang
- HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
- Westlake Center for Genome Editing, Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China.
- New Cornerstone Science Laboratory, Shenzhen, Guangdong, China.
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7
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Soares LW, King CG, Fernando CM, Roth A, Breaker RR. Genetic disruption of the bacterial raiA motif noncoding RNA causes defects in sporulation and aggregation. Proc Natl Acad Sci U S A 2024; 121:e2318008121. [PMID: 38306478 PMCID: PMC10861870 DOI: 10.1073/pnas.2318008121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/02/2023] [Indexed: 02/04/2024] Open
Abstract
Several structured noncoding RNAs in bacteria are essential contributors to fundamental cellular processes. Thus, discoveries of additional ncRNA classes provide opportunities to uncover and explore biochemical mechanisms relevant to other major and potentially ancient processes. A candidate structured ncRNA named the "raiA motif" has been found via bioinformatic analyses in over 2,500 bacterial species. The gene coding for the RNA typically resides between the raiA and comFC genes of many species of Bacillota and Actinomycetota. Structural probing of the raiA motif RNA from the Gram-positive anaerobe Clostridium acetobutylicum confirms key features of its sophisticated secondary structure model. Expression analysis of raiA motif RNA reveals that the RNA is constitutively produced but reaches peak abundance during the transition from exponential growth to stationary phase. The raiA motif RNA becomes the fourth most abundant RNA in C. acetobutylicum, excluding ribosomal RNAs and transfer RNAs. Genetic disruption of the raiA motif RNA causes cells to exhibit substantially decreased spore formation and diminished ability to aggregate. Restoration of normal cellular function in this knock-out strain is achieved by expression of a raiA motif gene from a plasmid. These results demonstrate that raiA motif RNAs normally participate in major cell differentiation processes by operating as a trans-acting factor.
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Affiliation(s)
- Lucas W. Soares
- Department of Microbial Pathogenesis, Yale University, New Haven, CT06536
| | - Christopher G. King
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511-8103
| | - Chrishan M. Fernando
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511-8103
| | - Adam Roth
- HHMI, Yale University, New Haven, CT06511-8103
| | - Ronald R. Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511-8103
- HHMI, Yale University, New Haven, CT06511-8103
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT06511-8103
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8
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Lyon SE, Wencker FDR, Fernando CM, Harris KA, Breaker RR. Disruption of the bacterial OLE RNP complex impairs growth on alternative carbon sources. PNAS NEXUS 2024; 3:pgae075. [PMID: 38415217 PMCID: PMC10898510 DOI: 10.1093/pnasnexus/pgae075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024]
Abstract
Ornate, large, extremophilic (OLE) RNAs comprise a class of large noncoding RNAs in bacteria whose members form a membrane-associated ribonucleoprotein (RNP) complex. This complex facilitates cellular adaptation to diverse stresses such as exposure to cold, short-chain alcohols, and elevated Mg2+ concentrations. Here, we report additional phenotypes exhibited by Halalkalibacterium halodurans (formerly called Bacillus halodurans) strains lacking functional OLE RNP complexes. Genetic disruption of the complex causes restricted growth compared to wild-type cells when cultured in minimal media (MM) wherein glucose is replaced with alternative carbon/energy sources. Genetic suppressor selections conducted in glutamate MM yielded isolates that carry mutations in or near genes relevant to Mn2+ homeostasis (ykoY and mntB), phosphate homeostasis (phoR), and putative multidrug resistance (bmrCD). These functional links between OLE RNA, carbon/energy management, and other fundamental processes including protein secretion are consistent with the hypothesis that the OLE RNP complex is a major contributor to cellular adaptation to unfavorable growth conditions.
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Affiliation(s)
- Seth E Lyon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Freya D R Wencker
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06511, USA
| | - Chrishan M Fernando
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Kimberly A Harris
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Ronald R Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06511, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
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9
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Wu Y, Zhu L, Zhang Y, Xu W. Multidimensional Applications and Challenges of Riboswitches in Biosensing and Biotherapy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304852. [PMID: 37658499 DOI: 10.1002/smll.202304852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/15/2023] [Indexed: 09/03/2023]
Abstract
Riboswitches have received significant attention over the last two decades for their multiple functionalities and great potential for applications in various fields. This article highlights and reviews the recent advances in biosensing and biotherapy. These fields involve a wide range of applications, such as food safety detection, environmental monitoring, metabolic engineering, live cell imaging, wearable biosensors, antibacterial drug targets, and gene therapy. The discovery, origin, and optimization of riboswitches are summarized to help readers better understand their multidimensional applications. Finally, this review discusses the multidimensional challenges and development of riboswitches in order to further expand their potential for novel applications.
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Affiliation(s)
- Yifan Wu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Yangzi Zhang
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Wentao Xu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
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10
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Salvail H, Balaji A, Roth A, Breaker RR. A spermidine riboswitch class in bacteria exploits a close variant of an aptamer for the enzyme cofactor S-adenosylmethionine. Cell Rep 2023; 42:113571. [PMID: 38096053 PMCID: PMC10853860 DOI: 10.1016/j.celrep.2023.113571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/16/2023] [Accepted: 11/22/2023] [Indexed: 12/30/2023] Open
Abstract
Natural polyamines such as spermidine and spermine cations have characteristics that make them highly likely to be sensed by riboswitches, such as their general affinity to polyanionic RNA and their broad contributions to cell physiology. Despite previous claims that polyamine riboswitches exist, evidence of their biological functions has remained unconvincing. Here, we report that rare variants of bacterial S-adenosylmethionine-I (SAM-I) riboswitches reject SAM and have adapted to selectively sense spermidine. These spermidine-sensing riboswitch variants are associated with genes whose protein products are directly involved in the production of spermidine and other polyamines. Biochemical and genetic assays demonstrate that representatives of this riboswitch class robustly function as genetic "off" switches, wherein spermidine binding causes premature transcription termination to suppress the expression of polyamine biosynthetic genes. These findings confirm the existence of natural spermidine-sensing riboswitches in bacteria and expand the list of variant riboswitch classes that have adapted to bind different ligands.
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Affiliation(s)
- Hubert Salvail
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
| | - Aparaajita Balaji
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
| | - Adam Roth
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA
| | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103, USA.
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11
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Liang X, Wang X. LncRNAs: Current understanding, future directions, and challenges. Animal Model Exp Med 2023; 6:505-507. [PMID: 38146076 PMCID: PMC10757209 DOI: 10.1002/ame2.12371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/03/2023] [Indexed: 12/27/2023] Open
Affiliation(s)
- Xiaolin Liang
- Department of Geriatrics, Gerontology Institute of Anhui Province, Centre for Leading Medicine and Advanced Technologies of IHM, The First Affiliated Hospital, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhuiChina
- Anhui Province Key Laboratory of Geriatric Immunology and Nutrition TherapyHefeiAnhuiChina
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Anhui Provincial Engineering Research Center for Elderly Care ProductsUniversity of Science and Technology of ChinaHefeiAnhuiChina
| | - Xiangting Wang
- Department of Geriatrics, Gerontology Institute of Anhui Province, Centre for Leading Medicine and Advanced Technologies of IHM, The First Affiliated Hospital, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhuiChina
- Anhui Province Key Laboratory of Geriatric Immunology and Nutrition TherapyHefeiAnhuiChina
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Anhui Provincial Engineering Research Center for Elderly Care ProductsUniversity of Science and Technology of ChinaHefeiAnhuiChina
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12
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Altae-Tran H, Kannan S, Suberski AJ, Mears KS, Demircioglu FE, Moeller L, Kocalar S, Oshiro R, Makarova KS, Macrae RK, Koonin EV, Zhang F. Uncovering the functional diversity of rare CRISPR-Cas systems with deep terascale clustering. Science 2023; 382:eadi1910. [PMID: 37995242 PMCID: PMC10910872 DOI: 10.1126/science.adi1910] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 09/28/2023] [Indexed: 11/25/2023]
Abstract
Microbial systems underpin many biotechnologies, including CRISPR, but the exponential growth of sequence databases makes it difficult to find previously unidentified systems. In this work, we develop the fast locality-sensitive hashing-based clustering (FLSHclust) algorithm, which performs deep clustering on massive datasets in linearithmic time. We incorporated FLSHclust into a CRISPR discovery pipeline and identified 188 previously unreported CRISPR-linked gene modules, revealing many additional biochemical functions coupled to adaptive immunity. We experimentally characterized three HNH nuclease-containing CRISPR systems, including the first type IV system with a specified interference mechanism, and engineered them for genome editing. We also identified and characterized a candidate type VII system, which we show acts on RNA. This work opens new avenues for harnessing CRISPR and for the broader exploration of the vast functional diversity of microbial proteins.
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Affiliation(s)
- Han Altae-Tran
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Soumya Kannan
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Anthony J. Suberski
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Kepler S. Mears
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - F. Esra Demircioglu
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Lukas Moeller
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Selin Kocalar
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Rachel Oshiro
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health; Bethesda, MD 20894, USA
| | - Rhiannon K. Macrae
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health; Bethesda, MD 20894, USA
| | - Feng Zhang
- Howard Hughes Medical Institute; Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- McGovern Institute for Brain Research at MIT; Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
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13
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Fremin BJ, Bhatt AS, Kyrpides NC. Identification of over ten thousand candidate structured RNAs in viruses and phages. Comput Struct Biotechnol J 2023; 21:5630-5639. [PMID: 38047235 PMCID: PMC10690425 DOI: 10.1016/j.csbj.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/03/2023] [Accepted: 11/03/2023] [Indexed: 12/05/2023] Open
Abstract
Structured RNAs play crucial roles in viruses, exerting influence over both viral and host gene expression. However, the extensive diversity of structured RNAs and their ability to act in cis or trans positions pose challenges for predicting and assigning their functions. While comparative genomics approaches have successfully predicted candidate structured RNAs in microbes on a large scale, similar efforts for viruses have been lacking. In this study, we screened over 5 million DNA and RNA viral sequences, resulting in the prediction of 10,006 novel candidate structured RNAs. These predictions are widely distributed across taxonomy and ecosystem. We found transcriptional evidence for 206 of these candidate structured RNAs in the human fecal microbiome. These candidate RNAs exhibited evidence of nucleotide covariation, indicative of selective pressure maintaining the predicted secondary structures. Our analysis revealed a diverse repertoire of candidate structured RNAs, encompassing a substantial number of putative tRNAs or tRNA-like structures, Rho-independent transcription terminators, and potentially cis-regulatory structures consistently positioned upstream of genes. In summary, our findings shed light on the extensive diversity of structured RNAs in viruses, offering a valuable resource for further investigations into their functional roles and implications in viral gene expression and pave the way for a deeper understanding of the intricate interplay between viruses and their hosts at the molecular level.
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Affiliation(s)
- Brayon J. Fremin
- Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ami S. Bhatt
- Blood and Marrow Transplantation) and Genetics, Stanford University, Stanford, CA, USA
- Department of Medicine (Hematology, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Nikos C. Kyrpides
- Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Lead Contact, USA
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14
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Hamal Dhakal S, Kavita K, Panchapakesan SSS, Roth A, Breaker RR. 8-oxoguanine riboswitches in bacteria detect and respond to oxidative DNA damage. Proc Natl Acad Sci U S A 2023; 120:e2307854120. [PMID: 37748066 PMCID: PMC10556655 DOI: 10.1073/pnas.2307854120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/25/2023] [Indexed: 09/27/2023] Open
Abstract
Riboswitches rely on structured aptamer domains to selectively sense their target ligands and regulate gene expression. However, some riboswitch aptamers in bacteria carry mutations in their otherwise strictly conserved binding pockets that change ligand specificities. The aptamer domain of a riboswitch class originally found to selectively sense guanine forms a three-stem junction that has since been observed to exploit numerous alterations in its ligand-binding pocket. These rare variants have modified their ligand specificities to sense other purines or purine derivatives, including adenine, 2'-deoxyguanosine (three classes), and xanthine. Herein, we report the characteristics of a rare variant that is narrowly distributed in the Paenibacillaceae family of bacteria. Known representatives are always associated with genes encoding 8-oxoguanine deaminase. As predicted from this gene association, these variant riboswitches tightly bind 8-oxoguanine (8-oxoG), strongly discriminate against other purine derivatives, and function as genetic "ON" switches. Following exposure of cells to certain oxidative stresses, a representative 8-oxoG riboswitch activates gene expression, likely caused by the accumulation of 8-oxoG due to oxidative damage to G nucleobases in DNA, RNA, and the nucleotide pool. Furthermore, an engineered version of the variant aptamer was prepared that exhibits specificity for 8-oxoadenine, further demonstrating that RNA aptamers can acquire mutations that expand their ability to detect and respond to oxidative damage.
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Affiliation(s)
- Siddhartha Hamal Dhakal
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT06511-8103
| | - Kumari Kavita
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT06511-8103
| | | | - Adam Roth
- HHMI, Yale University, New Haven, CT06511-8103
| | - Ronald R. Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT06511-8103
- HHMI, Yale University, New Haven, CT06511-8103
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511-8103
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15
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Li M, Deng J, Peng X, Wang J, Wilson TJ, Huang L, Lilley DMJ. Structure and ion-dependent folding of k-junctions. RNA (NEW YORK, N.Y.) 2023; 29:1411-1422. [PMID: 37311599 PMCID: PMC10573300 DOI: 10.1261/rna.079678.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/22/2023] [Indexed: 06/15/2023]
Abstract
k-Junctions are elaborated forms of kink turns with an additional helix on the nonbulged strand, thus forming a three-way helical junction. Two were originally identified in the structures of Arabidopsis and Escherichia coli thiamine pyrophosphate (TPP) riboswitches, and another called DUF-3268 was tentatively identified from sequence information. In this work we show that the Arabidopsis and E. coli riboswitch k-junctions fold in response to the addition of magnesium or sodium ions, and that atomic mutations that should disrupt key hydrogen bonding interactions greatly impair folding. Using X-ray crystallography, we have determined the structure of the DUF-3268 RNA and thus confirmed that it is a k-junction. It also folds upon the addition of metal ions, though requiring a 40-fold lower concentration of either divalent or monovalent ions. The key difference between the DUF-3268 and riboswitch k-junctions is the lack of nucleotides inserted between G1b and A2b in the former. We show that this insertion is primarily responsible for the difference in folding properties. Finally, we show that the DUF-3268 can functionally substitute for the k-junction in the E. coli TPP riboswitch such that the chimera can bind the TPP ligand, although less avidly.
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Affiliation(s)
- Mengxiao Li
- 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
| | - 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
| | - Jia Wang
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China
| | - Timothy J Wilson
- Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dundee DD1 5EH, United Kingdom
| | - 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
| | - David M J Lilley
- Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dundee DD1 5EH, United Kingdom
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16
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Xu J, Hou J, Ding M, Wang Z, Chen T. Riboswitches, from cognition to transformation. Synth Syst Biotechnol 2023; 8:357-370. [PMID: 37325181 PMCID: PMC10265488 DOI: 10.1016/j.synbio.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/20/2023] [Accepted: 05/25/2023] [Indexed: 06/17/2023] Open
Abstract
Riboswitches are functional RNA elements that regulate gene expression by directly detecting metabolites. Twenty years have passed since it was first discovered, researches on riboswitches are becoming increasingly standardized and refined, which could significantly promote people's cognition of RNA function as well. Here, we focus on some representative orphan riboswitches, enumerate the structural and functional transformation and artificial design of riboswitches including the coupling with ribozymes, hoping to attain a comprehensive understanding of riboswitch research.
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Affiliation(s)
- Jingdong Xu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Junyuan Hou
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Mengnan Ding
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Zhiwen Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Tao Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
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17
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Kornienko M, Bespiatykh D, Gorodnichev R, Abdraimova N, Shitikov E. Transcriptional Landscapes of Herelleviridae Bacteriophages and Staphylococcus aureus during Phage Infection: An Overview. Viruses 2023; 15:1427. [PMID: 37515114 PMCID: PMC10383478 DOI: 10.3390/v15071427] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/16/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
The issue of antibiotic resistance in healthcare worldwide has led to a pressing need to explore and develop alternative approaches to combat infectious diseases. Among these methods, phage therapy has emerged as a potential solution to tackle this growing challenge. Virulent phages of the Herelleviridae family, known for their ability to cause lysis of Staphylococcus aureus, a clinically significant pathogen frequently associated with multidrug resistance, have proven to be one of the most effective viruses utilized in phage therapy. In order to utilize phages for therapeutic purposes effectively, a thorough investigation into their physiology and mechanisms of action on infected cells is essential. The use of omics technologies, particularly total RNA sequencing, is a promising approach for analyzing the interaction between phages and their hosts, allowing for the assessment of both the behavior of the phage during infection and the cell's response. This review aims to provide a comprehensive overview of the physiology of the Herelleviridae family, utilizing existing analyses of their total phage transcriptomes. Additionally, it sheds light on the changes that occur in the metabolism of S. aureus when infected with virulent bacteriophages, contributing to a deeper understanding of the phage-host interaction.
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Affiliation(s)
- Maria Kornienko
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency Medicine, Moscow 119435, Russia
| | - Dmitry Bespiatykh
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency Medicine, Moscow 119435, Russia
| | - Roman Gorodnichev
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency Medicine, Moscow 119435, Russia
| | - Narina Abdraimova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency Medicine, Moscow 119435, Russia
| | - Egor Shitikov
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency Medicine, Moscow 119435, Russia
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18
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Narunsky A, Kavita K, Panchapakesan SSS, Fris ME, Breaker RR. A conserved uORF in the ilvBNC mRNA of Corynebacterium species regulates ilv operon expression. Microb Genom 2023; 9:mgen001019. [PMID: 37233150 PMCID: PMC10272879 DOI: 10.1099/mgen.0.001019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/23/2023] [Indexed: 05/27/2023] Open
Abstract
Computational methods can be used to identify putative structured noncoding RNAs (ncRNAs) in bacteria, which can then be validated using various biochemical and genetic approaches. In a search for ncRNAs in Corynebacterium pseudotuberculosis, we observed a conserved region called the ilvB-II motif located upstream of the ilvB gene that is also present in other members of this genus. This gene codes for an enzyme involved in the production of branched-chain amino acids (BCAAs). The ilvB gene in some bacteria is regulated by members of a ppGpp-sensing riboswitch class, but previous and current data suggest that the ilvB-II motif regulates expression by a transcription attenuation mechanism involving protein translation from an upstream open reading frame (uORF or leader peptide). All representatives of this RNA motif carry a start codon positioned in-frame with a nearby stop codon, and the peptides resulting from translation of this uORF are enriched for BCAAs, suggesting that expression of the ilvB gene in the host cells is controlled by attenuation. Furthermore, recently discovered RNA motifs also associated with ilvB genes in other bacterial species appear to carry distinct uORFs, suggesting that transcription attenuation by uORF translation is a common mechanism for regulating ilvB genes.
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Affiliation(s)
- Aya Narunsky
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Kumari Kavita
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | | | - Megan E. Fris
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06511, USA
- Present address: Abcam, Branford, CT 06405, USA
| | - Ronald R. Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06511, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
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19
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Ortega AD. Real-Time Assessment of Intracellular Metabolites in Single Cells through RNA-Based Sensors. Biomolecules 2023; 13:biom13050765. [PMID: 37238635 DOI: 10.3390/biom13050765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Quantification of the concentration of particular cellular metabolites reports on the actual utilization of metabolic pathways in physiological and pathological conditions. Metabolite concentration also constitutes the readout for screening cell factories in metabolic engineering. However, there are no direct approaches that allow for real-time assessment of the levels of intracellular metabolites in single cells. In recent years, the modular architecture of natural bacterial RNA riboswitches has inspired the design of genetically encoded synthetic RNA devices that convert the intracellular concentration of a metabolite into a quantitative fluorescent signal. These so-called RNA-based sensors are composed of a metabolite-binding RNA aptamer as the sensor domain, connected through an actuator segment to a signal-generating reporter domain. However, at present, the variety of available RNA-based sensors for intracellular metabolites is still very limited. Here, we go through natural mechanisms for metabolite sensing and regulation in cells across all kingdoms, focusing on those mediated by riboswitches. We review the design principles underlying currently developed RNA-based sensors and discuss the challenges that hindered the development of novel sensors and recent strategies to address them. We finish by introducing the current and potential applicability of synthetic RNA-based sensors for intracellular metabolites.
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Affiliation(s)
- Alvaro Darío Ortega
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University of Madrid, 28040 Madrid, Spain
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20
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Dunham DT, Angermeyer A, Seed KD. The RNA-RNA interactome between a phage and its satellite virus reveals a small RNA that differentially regulates gene expression across both genomes. Mol Microbiol 2023; 119:515-533. [PMID: 36786209 PMCID: PMC10392615 DOI: 10.1111/mmi.15046] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
Satellite viruses are present across all domains of life, defined as subviral parasites that require infection by another virus for satellite progeny production. Phage satellites exhibit various regulatory mechanisms to manipulate phage gene expression to the benefit of the satellite, redirecting resources from the phage to the satellite, and often inhibiting phage progeny production. While small RNAs (sRNAs) are well documented as regulators of prokaryotic gene expression, they have not been shown to play a regulatory role in satellite-phage conflicts. Vibrio cholerae encodes the phage inducible chromosomal island-like element (PLE), a phage satellite, to defend itself against the lytic phage ICP1. Here, we use Hi-GRIL-seq to identify a complex RNA-RNA interactome between PLE and ICP1. Both inter- and intragenome RNA interactions were detected, headlined by the PLE sRNA, SviR. SviR is involved in regulating both PLE and ICP1 gene expression uniquely, decreasing ICP1 target translation and affecting PLE transcripts. The striking conservation of SviR across all known PLEs suggests the sRNA is deeply rooted in the PLE-ICP1 conflict and implicates sRNAs as unidentified regulators of gene expression in phage-satellite interactions.
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Affiliation(s)
- Drew T Dunham
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
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21
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Kavita K, Breaker RR. Discovering riboswitches: the past and the future. Trends Biochem Sci 2023; 48:119-141. [PMID: 36150954 PMCID: PMC10043782 DOI: 10.1016/j.tibs.2022.08.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/18/2022] [Accepted: 08/26/2022] [Indexed: 01/25/2023]
Abstract
Riboswitches are structured noncoding RNA domains used by many bacteria to monitor the concentrations of target ligands and regulate gene expression accordingly. In the past 20 years over 55 distinct classes of natural riboswitches have been discovered that selectively sense small molecules or elemental ions, and thousands more are predicted to exist. Evidence suggests that some riboswitches might be direct descendants of the RNA-based sensors and switches that were likely present in ancient organisms before the evolutionary emergence of proteins. We provide an overview of the current state of riboswitch research, focusing primarily on the discovery of riboswitches, and speculate on the major challenges facing researchers in the field.
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Affiliation(s)
- Kumari Kavita
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
| | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103, USA.
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22
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Xu L, Xiao Y, Zhang J, Fang X. Structural insights into translation regulation by the THF-II riboswitch. Nucleic Acids Res 2023; 51:952-965. [PMID: 36620887 PMCID: PMC9881143 DOI: 10.1093/nar/gkac1257] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 01/10/2023] Open
Abstract
In bacteria, expression of folate-related genes is controlled by the tetrahydrofolate (THF) riboswitch in response to specific binding of THF and its derivatives. Recently, a second class of THF riboswitches, named THF-II, was identified in Gram-negative bacteria, which exhibit distinct architecture from the previously characterized THF-I riboswitches found in Gram-positive bacteria. Here, we present the crystal structures of the ligand-bound THF-II riboswitch from Mesorhizobium loti. These structures exhibit a long rod-like fold stabilized by continuous base pair and base triplet stacking across two helices of P1 and P2 and their interconnecting ligand-bound binding pocket. The pterin moiety of the ligand docks into the binding pocket by forming hydrogen bonds with two highly conserved pyrimidines in J12 and J21, which resembles the hydrogen-bonding pattern at the ligand-binding site FAPK in the THF-I riboswitch. Using small-angle X-ray scattering and isothermal titration calorimetry, we further characterized the riboswitch in solution and reveal that Mg2+ is essential for pre-organization of the binding pocket for efficient ligand binding. RNase H cleavage assay indicates that ligand binding reduces accessibility of the ribosome binding site in the right arm of P1, thus down-regulating the expression of downstream genes. Together, these results provide mechanistic insights into translation regulation by the THF-II riboswitch.
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Affiliation(s)
| | | | - Jie Zhang
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China,Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China
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23
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Xu X, Egger M, Li C, Chen H, Micura R, Ren A. Structure-based investigations of the NAD+-II riboswitch. Nucleic Acids Res 2023; 51:54-67. [PMID: 36610789 PMCID: PMC9841397 DOI: 10.1093/nar/gkac1227] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/07/2022] [Accepted: 12/10/2022] [Indexed: 01/09/2023] Open
Abstract
Riboswitches are conserved non-coding domains in bacterial mRNA with gene regulation function that are essential for maintaining enzyme co-factor metabolism. Recently, the pnuC RNA motif was reported to selectively bind nicotinamide adenine dinucleotide (NAD+), defining a novel class of NAD+ riboswitches (NAD+-II) according to phylogenetic analysis. To reveal the three-dimensional architecture and the ligand-binding mode of this riboswitch, we solved the crystal structure of NAD+-II riboswitch in complex with NAD+. Strikingly and in contrast to class-I riboswitches that form a tight recognition pocket for the adenosine diphosphate (ADP) moiety of NAD+, the class-II riboswitches form a binding pocket for the nicotinamide mononucleotide (NMN) portion of NAD+ and display only unspecific interactions with the adenosine. We support this finding by an additional structure of the class-II RNA in complex with NMN alone. The structures define a novel RNA tertiary fold that was further confirmed by mutational analysis in combination with isothermal titration calorimetry (ITC), and 2-aminopurine-based fluorescence spectroscopic folding studies. Furthermore, we truncated the pnuC RNA motif to a short RNA helical scaffold with binding affinity comparable to the wild-type motif to allude to the potential of engineering the NAD+-II motif for biotechnological applications.
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Affiliation(s)
| | | | | | - Hao Chen
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ronald Micura
- Correspondence may also be addressed to Ronald Micura.
| | - Aiming Ren
- To whom correspondence should be addressed. Tel: +86 571 88981228; Fax: +86 571 88981227;
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24
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Lenkeit F, Eckert I, Sinn M, Hauth F, Hartig JS, Weinberg Z. A variant of guanidine-IV riboswitches exhibits evidence of a distinct ligand specificity. RNA Biol 2023; 20:10-19. [PMID: 36548032 PMCID: PMC9788692 DOI: 10.1080/15476286.2022.2160562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Riboswitches are regulatory RNAs that specifically bind a small molecule or ion. Like metabolite-binding proteins, riboswitches can evolve new ligand specificities, and some examples of this phenomenon have been validated. As part of work based on comparative genomics to discover novel riboswitches, we encountered a candidate riboswitch with striking similarities to the recently identified guanidine-IV riboswitch. This candidate riboswitch, the Gd4v motif, is predicted in four distinct bacterial phyla, thus almost as widespread as the guanidine-IV riboswitch. Bioinformatic and experimental analysis suggest that the Gd4v motif is a riboswitch that binds a ligand other than guanidine. It is found associated with gene classes that differ from genes regulated by confirmed guanidine riboswitches. In inline-probing assays, we showed that free guanidine binds only weakly to one of the tested sequences of the variant. Further tested compounds did not show binding, attenuation of transcription termination, or activation of a genetic reporter construct. We characterized an N-acetyltransferase frequently associated with the Gd4v motif and compared its substrate preference to an N-acetyltransferase that occurs under control of guanidine-IV riboswitches. The substrates of this Gd4v-motif-associated enzyme did not show activity for Gd4v RNA binding or transcription termination. Hence, the ligand of the candidate riboswitch motif remains unidentified. The variant RNA motif is predominantly found in gut metagenome sequences, hinting at a ligand that is highly relevant in this environment. This finding is a first step to determining the identity of this unknown ligand, and understanding how guanidine-IV-riboswitch-like structures can evolve to bind different ligands.
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Affiliation(s)
- Felina Lenkeit
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457Konstanz, Germany
| | - Iris Eckert
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107Leipzig, Germany
| | - Malte Sinn
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457Konstanz, Germany
| | - Franziskus Hauth
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457Konstanz, Germany
| | - Jörg S. Hartig
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457Konstanz, Germany,CONTACT Jörg S. Hartig
| | - Zasha Weinberg
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107Leipzig, Germany,Zasha Weinberg Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107Leipzig, Germany
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25
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White N, Sadeeshkumar H, Sun A, Sudarsan N, Breaker RR. Lithium-sensing riboswitch classes regulate expression of bacterial cation transporter genes. Sci Rep 2022; 12:19145. [PMID: 36352003 PMCID: PMC9646797 DOI: 10.1038/s41598-022-20695-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/16/2022] [Indexed: 11/10/2022] Open
Abstract
Lithium is rare in Earth's crust compared to the biologically relevant alkali metal cations sodium and potassium but can accumulate to toxic levels in some environments. We report the experimental validation of two distinct bacterial riboswitch classes that selectively activate gene expression in response to elevated Li+ concentrations. These RNAs commonly regulate the expression of nhaA genes coding for ion transporters that weakly discriminate between Na+ and Li+. Our findings demonstrated that the primary function of Li+ riboswitches and associated NhaA transporters is to prevent Li+ toxicity, particularly when bacteria are living at high pH. Additional riboswitch-associated genes revealed how some cells defend against the deleterious effects of Li+ in the biosphere, which might become more problematic as its industrial applications increase.
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Affiliation(s)
- Neil White
- grid.47100.320000000419368710Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103 USA ,grid.47100.320000000419368710Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103 USA
| | - Harini Sadeeshkumar
- grid.47100.320000000419368710Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103 USA
| | - Anna Sun
- grid.47100.320000000419368710Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103 USA
| | - Narasimhan Sudarsan
- grid.47100.320000000419368710Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103 USA
| | - Ronald R. Breaker
- grid.47100.320000000419368710Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103 USA ,grid.47100.320000000419368710Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103 USA ,grid.47100.320000000419368710Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103 USA
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26
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Lyon SE, Harris KA, Odzer NB, Wilkins SG, Breaker RR. Ornate, large, extremophilic (OLE) RNA forms a kink turn necessary for OapC protein recognition and RNA function. J Biol Chem 2022; 298:102674. [PMID: 36336078 PMCID: PMC9723947 DOI: 10.1016/j.jbc.2022.102674] [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: 08/15/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 11/05/2022] Open
Abstract
Ornate, large, extremophilic (OLE) RNAs represent a class of noncoding RNAs prevalent in Gram-positive, extremophilic/anaerobic bacterial species. OLE RNAs (∼600 nt), whose precise biochemical functions remain mysterious, form an intricate secondary structure interspersed with regions of highly conserved nucleotides. In the alkali-halophilic bacterium Bacillus halodurans, OLE RNA is a component of a ribonucleoprotein (RNP) complex involving at least two proteins named OapA and OapB, but additional components may exist that could point to functional roles for the RNA. Disruption of the genes for either OLE RNA, OapA, or OapB result in the inability of cells to overcome cold, alcohol, or Mg2+ stresses. In the current study, we used in vivo crosslinking followed by OLE RNA isolation to identify the protein YbxF as a potential additional partner in the OLE RNP complex. Notably, a mutation in the gene for this same protein was also reported to be present in a strain wherein the complex is nonfunctional. The B. halodurans YbxF (herein renamed OapC) is homologous to a bacterial protein earlier demonstrated to bind kink turn (k-turn) RNA structural motifs. In vitro RNA-protein binding assays reveal that OLE RNA forms a previously unrecognized k-turn that serves as the natural binding site for YbxF/OapC. Moreover, B. halodurans cells carrying OLE RNAs with disruptive mutations in the k-turn exhibit phenotypes identical to cells lacking functional OLE RNP complexes. These findings reveal that the YbxF/OapC protein of B. halodurans is important for the formation of a functional OLE RNP complex.
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Affiliation(s)
- Seth E Lyon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Kimberly A Harris
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Nicole B Odzer
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Sarah G Wilkins
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Ronald R Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA; Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, USA.
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27
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Ono Y, Katayama K, Onuma T, Kubo K, Tsuyuzaki H, Hamada M, Sato M. Structure-based screening for functional non-coding RNAs in fission yeast identifies a factor repressing untimely initiation of sexual differentiation. Nucleic Acids Res 2022; 50:11229-11242. [PMID: 36259651 PMCID: PMC9638895 DOI: 10.1093/nar/gkac825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 09/06/2022] [Accepted: 09/14/2022] [Indexed: 12/04/2022] Open
Abstract
Non-coding RNAs (ncRNAs) ubiquitously exist in normal and cancer cells. Despite their prevalent distribution, the functions of most long ncRNAs remain uncharacterized. The fission yeast Schizosaccharomyces pombe expresses >1800 ncRNAs annotated to date, but most unconventional ncRNAs (excluding tRNA, rRNA, snRNA and snoRNA) remain uncharacterized. To discover the functional ncRNAs, here we performed a combinatory screening of computational and biological tests. First, all S. pombe ncRNAs were screened in silico for those showing conservation in sequence as well as in secondary structure with ncRNAs in closely related species. Almost a half of the 151 selected conserved ncRNA genes were uncharacterized. Twelve ncRNA genes that did not overlap with protein-coding sequences were next chosen for biological screening that examines defects in growth or sexual differentiation, as well as sensitivities to drugs and stresses. Finally, we highlighted an ncRNA transcribed from SPNCRNA.1669, which inhibited untimely initiation of sexual differentiation. A domain that was predicted as conserved secondary structure by the computational operations was essential for the ncRNA to function. Thus, this study demonstrates that in silico selection focusing on conservation of the secondary structure over species is a powerful method to pinpoint novel functional ncRNAs.
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Affiliation(s)
- Yu Ono
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Kenta Katayama
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Tomoki Onuma
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Kento Kubo
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Bioinformatics Laboratory, Department of Electrical Engineering and Bioscience, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555, Japan
| | - Hayato Tsuyuzaki
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Michiaki Hamada
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Bioinformatics Laboratory, Department of Electrical Engineering and Bioscience, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555, Japan.,Institute for Medical-oriented Structural Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Institute for Medical-oriented Structural Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
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28
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White N, Sadeeshkumar H, Sun A, Sudarsan N, Breaker RR. Na + riboswitches regulate genes for diverse physiological processes in bacteria. Nat Chem Biol 2022; 18:878-885. [PMID: 35879547 PMCID: PMC9337991 DOI: 10.1038/s41589-022-01086-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 06/10/2022] [Indexed: 01/31/2023]
Abstract
Organisms presumably have mechanisms to monitor and physiologically adapt to changes in cellular Na+ concentrations. Only a single bacterial protein has previously been demonstrated to selectively sense Na+ and regulate gene expression. Here we report a riboswitch class, previously called the 'DUF1646 motif', whose members selectively sense Na+ and regulate the expression of genes relevant to sodium biology. Many proteins encoded by Na+-riboswitch-regulated genes are annotated as metal ion transporters, whereas others are involved in mitigating osmotic stress or harnessing Na+ gradients for ATP production. Na+ riboswitches exhibit dissociation constants in the low mM range, and strongly reject all other alkali and alkaline earth ions. Likewise, only Na+ triggers riboswitch-mediated transcription and gene expression changes. These findings reveal that some bacteria use Na+ riboswitches to monitor, adjust and exploit Na+ concentrations and gradients, and in some instances collaborate with c-di-AMP riboswitches to coordinate gene expression during osmotic stress.
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Affiliation(s)
- Neil White
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
| | - Harini Sadeeshkumar
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Anna Sun
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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29
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Finstrlová A, Mašlaňová I, Blasdel Reuter BG, Doškař J, Götz F, Pantůček R. Global Transcriptomic Analysis of Bacteriophage-Host Interactions between a Kayvirus Therapeutic Phage and Staphylococcus aureus. Microbiol Spectr 2022; 10:e0012322. [PMID: 35435752 PMCID: PMC9241854 DOI: 10.1128/spectrum.00123-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/28/2022] [Indexed: 11/20/2022] Open
Abstract
Kayviruses are polyvalent broad host range staphylococcal phages with a potential to combat staphylococcal infections. However, the implementation of rational phage therapy in medicine requires a thorough understanding of the interactions between bacteriophages and pathogens at omics level. To evaluate the effect of a phage used in therapy on its host bacterium, we performed differential transcriptomic analysis by RNA-Seq from bacteriophage K of genus Kayvirus infecting two Staphylococcus aureus strains, prophage-less strain SH1000 and quadruple lysogenic strain Newman. The temporal transcriptional profile of phage K was comparable in both strains except for a few loci encoding hypothetical proteins. Stranded sequencing revealed transcription of phage noncoding RNAs that may play a role in the regulation of phage and host gene expression. The transcriptional response of S. aureus to phage K infection resembles a general stress response with differential expression of genes involved in a DNA damage response. The host transcriptional changes involved upregulation of nucleotide, amino acid and energy synthesis and transporter genes and downregulation of host transcription factors. The interaction of phage K with variable genetic elements of the host showed slight upregulation of gene expression of prophage integrases and antirepressors. The virulence genes involved in adhesion and immune evasion were only marginally affected, making phage K suitable for therapy. IMPORTANCE Bacterium Staphylococcus aureus is a common human and veterinary pathogen that causes mild to life-threatening infections. As strains of S. aureus are becoming increasingly resistant to multiple antibiotics, the need to search for new therapeutics is urgent. A promising alternative to antibiotic treatment of staphylococcal infections is a phage therapy using lytic phages from the genus Kayvirus. Here, we present a comprehensive view on the phage-bacterium interactions on transcriptomic level that improves the knowledge of molecular mechanisms underlying the Kayvirus lytic action. The results will ensure safer usage of the phage therapeutics and may also serve as a basis for the development of new antibacterial strategies.
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Affiliation(s)
- Adéla Finstrlová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ivana Mašlaňová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | | | - Jiří Doškař
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Roman Pantůček
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
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30
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Mestre MR, Gao LA, Shah SA, López-Beltrán A, González-Delgado A, Martínez-Abarca F, Iranzo J, Redrejo-Rodríguez M, Zhang F, Toro N. UG/Abi: a highly diverse family of prokaryotic reverse transcriptases associated with defense functions. Nucleic Acids Res 2022; 50:6084-6101. [PMID: 35648479 PMCID: PMC9226505 DOI: 10.1093/nar/gkac467] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/11/2022] [Accepted: 05/17/2022] [Indexed: 11/20/2022] Open
Abstract
Reverse transcriptases (RTs) are enzymes capable of synthesizing DNA using RNA as a template. Within the last few years, a burst of research has led to the discovery of novel prokaryotic RTs with diverse antiviral properties, such as DRTs (Defense-associated RTs), which belong to the so-called group of unknown RTs (UG) and are closely related to the Abortive Infection system (Abi) RTs. In this work, we performed a systematic analysis of UG and Abi RTs, increasing the number of UG/Abi members up to 42 highly diverse groups, most of which are predicted to be functionally associated with other gene(s) or domain(s). Based on this information, we classified these systems into three major classes. In addition, we reveal that most of these groups are associated with defense functions and/or mobile genetic elements, and demonstrate the antiphage role of four novel groups. Besides, we highlight the presence of one of these systems in novel families of human gut viruses infecting members of the Bacteroidetes and Firmicutes phyla. This work lays the foundation for a comprehensive and unified understanding of these highly diverse RTs with enormous biotechnological potential.
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Affiliation(s)
- Mario Rodríguez Mestre
- Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM) and Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Madrid, Spain
| | - Linyi Alex Gao
- Howard Hughes Medical Institute, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Society of Fellows, Harvard University, Cambridge, MA 02138, USA
| | - Shiraz A Shah
- Copenhagen Prospective Studies on Asthma in Childhood, Copenhagen University Hospital, Herlev-Gentofte, Ledreborg Allé 34, DK-2820 Gentofte, Denmark
| | - Adrián López-Beltrán
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - Alejandro González-Delgado
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Structure, Dynamics and Function of Rhizobacterial Genomes, Grupo de Ecología Genética de la Rizosfera, Spain
| | - Francisco Martínez-Abarca
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Structure, Dynamics and Function of Rhizobacterial Genomes, Grupo de Ecología Genética de la Rizosfera, Spain
| | - Jaime Iranzo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Zaragoza, Spain
| | - Modesto Redrejo-Rodríguez
- Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM) and Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Madrid, Spain
| | - Feng Zhang
- Howard Hughes Medical Institute, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicolás Toro
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Structure, Dynamics and Function of Rhizobacterial Genomes, Grupo de Ecología Genética de la Rizosfera, Spain
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Hamal Dhakal S, Panchapakesan SSS, Slattery P, Roth A, Breaker RR. Variants of the guanine riboswitch class exhibit altered ligand specificities for xanthine, guanine, or 2'-deoxyguanosine. Proc Natl Acad Sci U S A 2022; 119:e2120246119. [PMID: 35622895 PMCID: PMC9295807 DOI: 10.1073/pnas.2120246119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/12/2022] [Indexed: 12/30/2022] Open
Abstract
The aptamer portions of previously reported riboswitch classes that sense guanine, adenine, or 2′-deoxyguanosine are formed by a highly similar three-stem junction with distinct nucleotide sequences in the regions joining the stems. The nucleotides in these joining regions form the major features of the selective ligand-binding pocket for each aptamer. Previously, we reported the existence of additional, rare variants of the predominant guanine-sensing riboswitch class that carry nucleotide differences in the ligand-binding pocket, suggesting that these RNAs have further diversified their structures and functions. Herein, we report the discovery and analysis of three naturally occurring variants of guanine riboswitches that are narrowly distributed across Firmicutes. These RNAs were identified using comparative sequence analysis methods, which also revealed that some of the gene associations for these variants are atypical for guanine riboswitches or their previously known natural variants. Binding assays demonstrate that the newfound variant riboswitch representatives recognize xanthine, guanine, or 2′-deoxyguanosine, with the guanine class exhibiting greater discrimination against related purines than the more common guanine riboswitch class reported previously. These three additional variant classes, together with the four previously discovered riboswitch classes that employ the same three-stem junction architecture, reveal how a simple structural framework can be diversified to expand the range of purine-based ligands sensed by RNA.
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Affiliation(s)
- Siddhartha Hamal Dhakal
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103
| | | | - Paul Slattery
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103
| | - Adam Roth
- HHMI, Yale University, New Haven, CT 06520-8103
| | - Ronald R. Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103
- HHMI, Yale University, New Haven, CT 06520-8103
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103
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32
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Zhang M, Liu G, Zhang Y, Chen T, Feng S, Cai R, Lu C. The Second Class of Tetrahydrofolate (THF-II) Riboswitches Recognizes the Tetrahydrofolic Acid Ligand via Local Conformation Changes. Int J Mol Sci 2022; 23:ijms23115903. [PMID: 35682583 PMCID: PMC9180208 DOI: 10.3390/ijms23115903] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/02/2022] [Accepted: 05/06/2022] [Indexed: 02/05/2023] Open
Abstract
Riboswitches are regulatory noncoding RNAs found in bacteria, fungi and plants, that modulate gene expressions through structural changes in response to ligand binding. Understanding how ligands interact with riboswitches in solution can shed light on the molecular mechanisms of this ancient regulators. Previous studies showed that riboswitches undergo global conformation changes in response to ligand binding to relay information. Here, we report conformation switching models of the recently discovered tetrahydrofolic acid-responsive second class of tetrahydrofolate (THF-II) riboswitches in response to ligand binding. Using a combination of selective 2′-hydroxyl acylation, analyzed by primer extension (SHAPE) assay, 3D modeling and small-angle X-ray scattering (SAXS), we found that the ligand specifically recognizes and reshapes the THF-II riboswitch loop regions, but does not affect the stability of the P3 helix. Our results show that the THF-II riboswitch undergoes only local conformation changes in response to ligand binding, rearranging the Loop1-P3-Loop2 region and rotating Loop1 from a ~120° angle to a ~75° angle. This distinct conformation changes suggest a unique regulatory mechanism of the THF-II riboswitch, previously unseen in other riboswitches. Our findings may contribute to the fields of RNA sensors and drug design.
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Affiliation(s)
- Minmin Zhang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Guangfeng Liu
- National Center for Protein Science Shanghai, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China;
| | - Yunlong Zhang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Ting Chen
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Shanshan Feng
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Rujie Cai
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
- Correspondence: (R.C.); (C.L.); Tel.: +86-21-6779-2740 (C.L.)
| | - Changrui Lu
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
- Correspondence: (R.C.); (C.L.); Tel.: +86-21-6779-2740 (C.L.)
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Abstract
Noncoding RNAs with secondary structures play important roles in CRISPR-Cas systems. Many of these structures likely remain undiscovered. We used a large-scale comparative genomics approach to predict 156 novel candidate structured RNAs from 36,111 CRISPR-Cas systems. A number of these were found to overlap with coding genes, including palindromic candidates that overlapped with a variety of Cas genes in type I and III systems. Among these 156 candidates, we identified 46 new models of CRISPR direct repeats and 1 tracrRNA. This tracrRNA model occasionally overlapped with predicted cas9 coding regions, emphasizing the importance of expanding our search windows for novel structure RNAs in coding regions. We also demonstrated that the antirepeat sequence in this tracrRNA model can be used to accurately assign thousands of predicted CRISPR arrays to type II-C systems. This study highlights the importance of unbiased identification of candidate structured RNAs across CRISPR-Cas systems.
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Affiliation(s)
- Brayon J. Fremin
- Department of Energy, Joint Genome Institute, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Nikos C. Kyrpides
- Department of Energy, Joint Genome Institute, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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34
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Pinatel E, Calcagnile M, Talà A, Damiano F, Siculella L, Peano C, De Benedetto GE, Pennetta A, De Bellis G, Alifano P. Interplay between non-coding RNA transcription, stringent phenotype and antibiotic production in Streptomyces. J Biotechnol 2022:S0168-1656(22)00029-3. [PMID: 35182607 DOI: 10.1016/j.jbiotec.2022.02.006] [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: 01/15/2021] [Accepted: 02/12/2022] [Indexed: 11/26/2022]
Abstract
While in recent years the key role of non-coding RNAs (ncRNAs) in regulation of gene expression has become increasingly evident, their interaction with the global regulatory circuits is still obscure. Here we analyzed the structure and organization of the transcriptome of Streptomyces ambofaciens, the producer of spiramycin. We identified ncRNAs including 45 small-RNAs (sRNAs) and 119 antisense-RNAs (asRNAs I) that appear transcribed from dedicated promoters. Some sRNAs and asRNAs are unprecedented in Streptomyces, and were predicted to target mRNAs encoding proteins involved in transcription, translation, ribosomal structure and biogenesis, and regulation of morphological and biochemical differentiation. We then compared ncRNA expression in three strains: i.) the wild type strain; ii.) an isogenic pirA-defective mutant with central carbon metabolism imbalance, "relaxed" phenotype, and repression of antibiotic production; iii.) a pirA-derivative strain harboring a "stringent" RNA polymerase that suppresses pirA-associated phenotypes. Data indicated that expression of most ncRNAs was correlated to the stringent/relaxed phenotype suggesting novel effector mechanisms of the stringent response.
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Affiliation(s)
- Eva Pinatel
- Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy
| | - Matteo Calcagnile
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni, 73100 Lecce, Italy
| | - Adelfia Talà
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni, 73100 Lecce, Italy
| | - Fabrizio Damiano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni, 73100 Lecce, Italy
| | - Luisa Siculella
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni, 73100 Lecce, Italy
| | - Clelia Peano
- Genomic Unit, IRCCS Humanitas Clinical and Research Center, Rozzano, Milan, Italy; Institute of Genetic and Biomedical Research, UoS of Milan, National Research Council, Rozzano, Milan, Italy
| | | | - Antonio Pennetta
- Department of Cultural Heritage, University of Salento, Via Monteroni, 73100 Lecce, Italy
| | - Gianluca De Bellis
- Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy
| | - Pietro Alifano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni, 73100 Lecce, Italy.
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35
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Abstract
More than 55 distinct classes of riboswitches that respond to small metabolites or elemental ions have been experimentally validated to date. The ligands sensed by these riboswitches are biased in favor of fundamental compounds or ions that are likely to have been relevant to ancient forms of life, including those that might have populated the "RNA World", which is a proposed biochemical era that predates the evolutionary emergence of DNA and proteins. In the following text, I discuss the various types of ligands sensed by some of the most common riboswitches present in modern bacterial cells and consider implications for ancient biological processes centered on the proven capabilities of these RNA-based sensors. Although most major biochemical aspects of metabolism are represented by known riboswitch classes, there are striking sensory gaps in some key areas. These gaps could reveal weaknesses in the performance capabilities of RNA that might have hampered RNA World evolution, or these could highlight opportunities to discover additional riboswitch classes that sense essential metabolites.
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Affiliation(s)
- Ronald R. Breaker
- Corresponding Author: Ronald R. Breaker - Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, United States; Phone: 203-432-9389; , Twitter: @RonBreaker
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36
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Wu Y, Zhang D, Duan A, Ao Y, Li S. The application of riboswitch sequencing for human gut bacterial classification and identification. Mol Phylogenet Evol 2022; 169:107409. [PMID: 35063674 DOI: 10.1016/j.ympev.2022.107409] [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: 07/23/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 11/15/2022]
Abstract
Bacteria, especially gut bacteria play important roles in human health and diseases. The classification of many bacterial genera by the 16S ribosomal RNA (rRNA) has failed due to its low inter-species resolution. Given the wide distribution of riboswitches in bacteria, they may help 16S rRNA differentiate closely related species. We found that among 28 groups of species that could not be distinguished by 16S rRNA, eight of them could be separated by the TPP riboswitch and other riboswitches. Moreover, the species in the 16S rRNA database and these riboswitch databases overlap, therefore, using riboswitch databases can help 16S rRNA better identify species. In addition, we used Klenow DNA polymerase and a pair of short primers to facilitate the library construction of TPP riboswitches for sequencing. The sequencing results showed that the TPP riboswitch could detect the major phyla similar to those detected by 16S rRNA. Therefore, the TPP riboswitch and other riboswitch classes could potentially be applied to gut bacteria classification.
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Affiliation(s)
- Yaoyao Wu
- Medical School, Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Precision Medicine and Molecular Diagnosis of Fujian Universities, Institute of Genomics, School of Biomedical Sciences, Huaqiao University, Xiamen, 361021, P. R. China
| | - Deying Zhang
- Medical School, Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Precision Medicine and Molecular Diagnosis of Fujian Universities, Institute of Genomics, School of Biomedical Sciences, Huaqiao University, Xiamen, 361021, P. R. China; State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510627, P. R. China(2)
| | - Anqi Duan
- Medical School, Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Precision Medicine and Molecular Diagnosis of Fujian Universities, Institute of Genomics, School of Biomedical Sciences, Huaqiao University, Xiamen, 361021, P. R. China
| | - Yaqi Ao
- Medical School, Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Precision Medicine and Molecular Diagnosis of Fujian Universities, Institute of Genomics, School of Biomedical Sciences, Huaqiao University, Xiamen, 361021, P. R. China
| | - Sanshu Li
- Medical School, Engineering Research Center of Molecular Medicine of Ministry of Education, Key Laboratory of Precision Medicine and Molecular Diagnosis of Fujian Universities, Institute of Genomics, School of Biomedical Sciences, Huaqiao University, Xiamen, 361021, P. R. China.
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37
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Sherlock ME, Higgs G, Yu D, Widner DL, White NA, Sudarsan N, Sadeeshkumar H, Perkins KR, Mirihana Arachchilage G, Malkowski SN, King CG, Harris KA, Gaffield G, Atilho RM, Breaker RR. Architectures and complex functions of tandem riboswitches. RNA Biol 2022; 19:1059-1076. [PMID: 36093908 PMCID: PMC9481103 DOI: 10.1080/15476286.2022.2119017] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Riboswitch architectures that involve the binding of a single ligand to a single RNA aptamer domain result in ordinary dose-response curves that require approximately a 100-fold change in ligand concentration to cover nearly the full dynamic range for gene regulation. However, by using multiple riboswitches or aptamer domains in tandem, these ligand-sensing structures can produce additional, complex gene control outcomes. In the current study, we have computationally searched for tandem riboswitch architectures in bacteria to provide a more complete understanding of the diverse biological and biochemical functions of gene control elements that are made exclusively of RNA. Numerous different arrangements of tandem homologous riboswitch architectures are exploited by bacteria to create more 'digital' gene control devices, which operate over a narrower ligand concentration range. Also, two heterologous riboswitch aptamers are sometimes employed to create two-input Boolean logic gates with various types of genetic outputs. These findings illustrate the sophisticated genetic decisions that can be made by using molecular sensors and switches based only on RNA.
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Affiliation(s)
- Madeline E. Sherlock
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Research-1S, Aurora, CO, USA
| | - Gadareth Higgs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Diane Yu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Danielle L. Widner
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Neil A. White
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Harini Sadeeshkumar
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Kevin R. Perkins
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Gayan Mirihana Arachchilage
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
| | | | - Christopher G. King
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | | | - Glenn Gaffield
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Ruben M. Atilho
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Ronald R. Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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38
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Roth A, Weinberg Z, Vanderschuren K, Murdock MH, Breaker RR. Natural circularly permuted group II introns in bacteria produce RNA circles. iScience 2021; 24:103431. [PMID: 34901790 PMCID: PMC8637638 DOI: 10.1016/j.isci.2021.103431] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/20/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Abstract
Group II self-splicing introns are large structured RNAs that remove themselves from transcripts while simultaneously sealing the resulting gaps. Some representatives can subsequently reverse splice into DNA, accounting for their pervasive distribution in bacteria. The catalytically active tertiary structure of each group II intron is assembled from six domains that are arranged in a conserved order. Here, we report structural isomers of group II introns, called CP group II ribozymes, wherein the characteristic order of domains has been altered. Domains five and six, which normally reside at the 3' end of group II introns, instead occupy the 5' end to form circularly permuted variants. These unusual group II intron derivatives are catalytically active and generate large linear branched and small circular RNAs, reaction products that are markedly different from those generated by canonical group II introns. The biological role of CP group II ribozymes is currently unknown.
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Affiliation(s)
- Adam Roth
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA
| | - Zasha Weinberg
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA
| | - Koen Vanderschuren
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
| | - Mitchell H. Murdock
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
| | - Ronald R. Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103, USA
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39
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Olzog VJ, Gärtner C, Stadler PF, Fallmann J, Weinberg CE. cyPhyRNA-seq: a genome-scale RNA-seq method to detect active self-cleaving ribozymes by capturing RNAs with 2',3' cyclic phosphates and 5' hydroxyl ends. RNA Biol 2021; 18:818-831. [PMID: 34906034 PMCID: PMC8782182 DOI: 10.1080/15476286.2021.1999105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Self-cleaving ribozymes are catalytically active RNAs that cleave themselves into a 5′-fragment with a 2′,3′-cyclic phosphate and a 3′-fragment with a 5′-hydroxyl. They are widely applied for the construction of synthetic RNA devices and RNA-based therapeutics. However, the targeted discovery of self-cleaving ribozymes remains a major challenge. We developed a transcriptome-wide method, called cyPhyRNA-seq, to screen for ribozyme cleavage fragments in total RNA extract. This approach employs the specific ligation-based capture of ribozyme 5′-fragments using a variant of the Arabidopsis thaliana tRNA ligase we engineered. To capture ribozyme 3′-fragments, they are enriched from total RNA by enzymatic treatments. We optimized and enhanced the individual steps of cyPhyRNA-seq in vitro and in spike-in experiments. Then, we applied cyPhyRNA-seq to total RNA isolated from the bacterium Desulfovibrio vulgaris and detected self-cleavage of the three predicted type II hammerhead ribozymes, whose activity had not been examined to date. cyPhyRNA-seq can be used for the global analysis of active self-cleaving ribozymes with the advantage to capture both ribozyme cleavage fragments from total RNA. Especially in organisms harbouring many self-cleaving RNAs, cyPhyRNA-seq facilitates the investigation of cleavage activity. Moreover, this method has the potential to be used to discover novel self-cleaving ribozymes in different organisms.
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Affiliation(s)
- V Janett Olzog
- Department of Life Science, Institute for Biochemistry, Leipzig, Germany
| | - Christiane Gärtner
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Department of Theoretical Chemistry, Vienna, Austria.,Facultad de Ciencias, Universidad National de Colombia, Sede Bogotá, Colombia.,Santa Fe Institute, University of Vienna, Santa Fe, New Mexico, USA
| | - Jörg Fallmann
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
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40
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Affiliation(s)
- Gavin J Knott
- Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia; Arizona State University, Tempe, Arizona, USA
| | - Audrone Lapinaite
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA; and Arizona State University, Tempe, Arizona, USA.,Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Arizona State University, Tempe, Arizona, USA
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41
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Smith-Peter E, Séguin DL, St-Pierre É, Sekulovic O, Jeanneau S, Tremblay-Tétreault C, Lamontagne AM, Jacques PÉ, Lafontaine DA, Fortier LC. Inactivation of the riboswitch-controlled GMP synthase GuaA in Clostridioides difficile is associated with severe growth defects and poor infectivity in a mouse model of infection. RNA Biol 2021; 18:699-710. [PMID: 34612173 DOI: 10.1080/15476286.2021.1978768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Clostridioides difficile is the main cause of nosocomial antibiotic-associated diarrhoea. There is a need for new antimicrobials to tackle this pathogen. Guanine riboswitches have been proposed as promising new antimicrobial targets, but experimental evidence of their importance in C. difficile is missing. The genome of C. difficile encodes four distinct guanine riboswitches, each controlling a single gene involved in purine metabolism and transport. One of them controls the expression of guaA, encoding a guanosine monophosphate (GMP) synthase. Here, using in-line probing and GusA reporter assays, we show that these riboswitches are functional in C. difficile and cause premature transcription termination upon binding of guanine. All riboswitches exhibit a high affinity for guanine characterized by Kd values in the low nanomolar range. Xanthine and guanosine also bind the guanine riboswitches, although with less affinity. Inactivating the GMP synthase (guaA) in C. difficile strain 630 led to cell death in minimal growth conditions, but not in rich medium. Importantly, the capacity of a guaA mutant to colonize the mouse gut was significantly reduced. Together, these results demonstrate the importance of de novo GMP biosynthesis in C. difficile during infection, suggesting that targeting guanine riboswitches with analogues could be a viable therapeutic strategy.
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Affiliation(s)
- Erich Smith-Peter
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université De Sherbrooke, Sherbrooke, Quebec, Canada.,Department of Biology, Faculty of Science, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - David Lalonde Séguin
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Émilie St-Pierre
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Ognjen Sekulovic
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Simon Jeanneau
- Department of Biology, Faculty of Science, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | | | - Anne-Marie Lamontagne
- Department of Biology, Faculty of Science, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Pierre-Étienne Jacques
- Department of Biology, Faculty of Science, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Daniel A Lafontaine
- Department of Biology, Faculty of Science, Université De Sherbrooke, Sherbrooke, Quebec, Canada
| | - Louis-Charles Fortier
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université De Sherbrooke, Sherbrooke, Quebec, Canada
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42
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Altae-Tran H, Kannan S, Demircioglu FE, Oshiro R, Nety SP, McKay LJ, Dlakić M, Inskeep WP, Makarova KS, Macrae RK, Koonin EV, Zhang F. The widespread IS200/IS605 transposon family encodes diverse programmable RNA-guided endonucleases. Science 2021; 374:57-65. [PMID: 34591643 PMCID: PMC8929163 DOI: 10.1126/science.abj6856] [Citation(s) in RCA: 173] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
IscB proteins are putative nucleases encoded in a distinct family of IS200/IS605 transposons and are likely ancestors of the RNA-guided endonuclease Cas9, but the functions of IscB and its interactions with any RNA remain uncharacterized. Using evolutionary analysis, RNA sequencing, and biochemical experiments, we reconstructed the evolution of CRISPR-Cas9 systems from IS200/IS605 transposons. We found that IscB uses a single noncoding RNA for RNA-guided cleavage of double-stranded DNA and can be harnessed for genome editing in human cells. We also demonstrate the RNA-guided nuclease activity of TnpB, another IS200/IS605 transposon-encoded protein and the likely ancestor of Cas12 endonucleases. This work reveals a widespread class of transposon-encoded RNA-guided nucleases, which we name OMEGA (obligate mobile element–guided activity), with strong potential for developing as biotechnologies.
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Affiliation(s)
- Han Altae-Tran
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Soumya Kannan
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - F. Esra Demircioglu
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Rachel Oshiro
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Suchita P. Nety
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Luke J. McKay
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
- Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA
- Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717
| | - Mensur Dlakić
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - William P. Inskeep
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
- Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Rhiannon K. Macrae
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Feng Zhang
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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43
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Brewer KI, Gaffield GJ, Puri M, Breaker RR. DIMPL: a bioinformatics pipeline for the discovery of structured noncoding RNA motifs in bacteria. Bioinformatics 2021; 38:533-535. [PMID: 34524415 PMCID: PMC8723152 DOI: 10.1093/bioinformatics/btab624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 05/07/2021] [Accepted: 09/10/2021] [Indexed: 02/03/2023] Open
Abstract
SUMMARY Recent efforts to identify novel bacterial structured noncoding RNA (ncRNA) motifs through searching long, GC-rich intergenic regions (IGRs) have revealed several new classes, including the recently validated HMP-PP riboswitch. The DIMPL (Discovery of Intergenic Motifs PipeLine) discovery pipeline described herein enables rapid extraction and selection of bacterial IGRs that are enriched for structured ncRNAs. Moreover, DIMPL automates the subsequent computational steps necessary for their functional identification. AVAILABILITY AND IMPLEMENTATION The DIMPL pipeline is freely available as a Docker image with an accompanying set of Jupyter notebooks. Full instructions for download and use are available at https://github.com/breakerlab/dimpl. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Kenneth I Brewer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8103, USA
| | - Glenn J Gaffield
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8103, USA
| | - Malavika Puri
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103, USA
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44
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Interplay between Non-Coding RNA Transcription, Stringent/Relaxed Phenotype and Antibiotic Production in Streptomyces ambofaciens. Antibiotics (Basel) 2021; 10:antibiotics10080947. [PMID: 34438997 PMCID: PMC8388888 DOI: 10.3390/antibiotics10080947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/28/2021] [Accepted: 08/02/2021] [Indexed: 11/25/2022] Open
Abstract
While in recent years the key role of non-coding RNAs (ncRNAs) in the regulation of gene expression has become increasingly evident, their interaction with the global regulatory circuits is still obscure. Here we analyzed the structure and organization of the transcriptome of Streptomyces ambofaciens, the producer of spiramycin. We identified ncRNAs including 45 small-RNAs (sRNAs) and 119 antisense-RNAs (asRNAs I) that appear transcribed from dedicated promoters. Some sRNAs and asRNAs are unprecedented in Streptomyces and were predicted to target mRNAs encoding proteins involved in transcription, translation, ribosomal structure and biogenesis, and regulation of morphological and biochemical differentiation. We then compared ncRNA expression in three strains: (i) the wild-type strain; (ii) an isogenic pirA-defective mutant with central carbon metabolism imbalance, “relaxed” phenotype, and repression of antibiotic production; and (iii) a pirA-derivative strain harboring a “stringent” RNA polymerase that suppresses pirA-associated phenotypes. Data indicated that the expression of most ncRNAs was correlated to the stringent/relaxed phenotype suggesting novel effector mechanisms of the stringent response.
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45
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Nakashima Y, Shiiyama N, Urabe T, Yamashita H, Yasuda S, Igoshi K, Kinoshita H. Functions of small RNAs in Lactobacillus casei-Pediococcus group of lactic acid bacteria using fragment analysis. FEMS Microbiol Lett 2021; 367:5928547. [PMID: 33068404 DOI: 10.1093/femsle/fnaa154] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Small RNAs (sRNA) are non-cording RNAs composed of 50∼400 nt responsible for coordinating the adaption of Escherichia coli and other bacteria to changing environmental conditions, including pH and temperature. However, the role of sRNAs in lactic acid bacteria (LAB) has not yet been clarified. In this study, we used the Lactobacillus casei-Pediococcus group to evaluate the function of sRNAs in LAB, using RNA sequencing in the exponential growth phase and stationary phase to map and analyze sRNA fragments, which were categorized as Pediococcus pentosaceus and Lactobacillus paracasei. We evaluated the role of sRNAs in nutrient synthesis for cell growth in exponential growth phase and in protein and biofilm biosynthesis for cell body durability. During exponential growth, the sRNA fragments were found to be involved in the stress response in Pediococcus pentosaceus and in environmental adaption in Lactobacillus paracasei. The results suggest that the function of sRNA can be characterized from sRNA fragments using RNA sequencing during the exponential growth and stationary phases in Lactobacillus casei-Pediococcus group.
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Affiliation(s)
- Yuki Nakashima
- Graduate School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Narumi Shiiyama
- Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Taihei Urabe
- Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Hideji Yamashita
- Graduate School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan.,Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Shin Yasuda
- Graduate School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan.,Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Keiji Igoshi
- Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
| | - Hideki Kinoshita
- Graduate School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan.,Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto, Japan
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46
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Huang L, Liao X, Li M, Wang J, Peng X, Wilson TJ, Lilley DMJ. Structure and folding of four putative kink turns identified in structured RNA species in a test of structural prediction rules. Nucleic Acids Res 2021; 49:5916-5924. [PMID: 33978763 PMCID: PMC8191799 DOI: 10.1093/nar/gkab333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/13/2021] [Accepted: 05/09/2021] [Indexed: 01/25/2023] Open
Abstract
k-Turns are widespread key architectural elements that occur in many classes of RNA molecules. We have shown previously that their folding properties (whether or not they fold into their tightly kinked structure on addition of metal ions) and conformation depend on their local sequence, and we have elucidated a series of rules for prediction of these properties from sequence. In this work, we have expanded the rules for prediction of folding properties, and then applied the full set to predict the folding and conformation of four probable k-turns we have identified amongst 224 structured RNA species found in bacterial intergenenic regions by the Breaker lab (1). We have analyzed the ion-dependence of folding of the four k-turns using fluorescence resonance energy transfer, and determined the conformation of two of them using X-ray crystallography. We find that the experimental data fully conform to both the predicted folding and conformational properties. We conclude that our folding rules are robust, and can be applied to new k-turns of unknown characteristics with confidence.
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Affiliation(s)
- Lin Huang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, PR China
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Xinli Liao
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China
| | - Mengxiao Li
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, PR China
| | - Jia Wang
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Xuemei Peng
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, PR China
| | - Timothy J Wilson
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - David M J Lilley
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, UK
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47
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Brewer KI, Greenlee EB, Higgs G, Yu D, Mirihana Arachchilage G, Chen X, King N, White N, Breaker RR. Comprehensive discovery of novel structured noncoding RNAs in 26 bacterial genomes. RNA Biol 2021; 18:2417-2432. [PMID: 33970790 PMCID: PMC8632094 DOI: 10.1080/15476286.2021.1917891] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2022] Open
Abstract
Comparative sequence analysis methods are highly effective for uncovering novel classes of structured noncoding RNAs (ncRNAs) from bacterial genomic DNA sequence datasets. Previously, we developed a computational pipeline to more comprehensively identify structured ncRNA representatives from individual bacterial genomes. This search process exploits the fact that genomic regions serving as templates for the transcription of structured RNAs tend to be present in longer than average noncoding 'intergenic regions' (IGRs) that are enriched in G and C nucleotides compared to the remainder of the genome. In the present study, we apply this computational pipeline to identify structured ncRNA candidates from 26 diverse bacterial species. Numerous novel structured ncRNA motifs were discovered, including several riboswitch candidates, one whose ligand has been identified and others that have yet to be experimentally validated. Our findings support recent predictions that hundreds of novel ribo-switch classes and other ncRNAs remain undiscovered among the limited number of bacterial species whose genomes have been completely sequenced.
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Affiliation(s)
- Kenneth I Brewer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Etienne B Greenlee
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Gadareth Higgs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Diane Yu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Xi Chen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Nicholas King
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Neil White
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
| | - Ronald R Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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48
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Cubi R, Bouhedda F, Collot M, Klymchenko AS, Ryckelynck M. µIVC-Useq: a microfluidic-assisted high-throughput functionnal screening in tandem with next generation sequencing and artificial neural network to rapidly characterize RNA molecules. RNA (NEW YORK, N.Y.) 2021; 27:rna.077586.120. [PMID: 33952671 PMCID: PMC8208054 DOI: 10.1261/rna.077586.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 05/01/2021] [Indexed: 05/10/2023]
Abstract
The function of an RNA is intimately linked to its three-dimensional structure. X-ray crystallography or NMR allow the fine structural characterization of small RNA (e.g., aptamers) with a precision down to atomic resolution. Yet, these technics are time consuming, laborious and do not inform on mutational robustness and the extent to which a sequence can be modified without altering RNA function, an important set of information to assist RNA engineering. On another hand, thought powerful, in silico predictions still lack the required accuracy. These limitations can be overcome by using high-throughput microfluidic-assisted functional screening technologies, as they allow exploring large mutant libraries in a rapid and cost-effective manner. Among them, we recently introduced the microfluidic-assisted In Vitro Compartmentalization (µIVC), an efficient screening strategy in which reactions are performed in picoliter droplets at rates of several thousand per second. We later improved µIVC efficiency by using in tandem with high throughput sequencing, thought a laborious bioinformatic step was still required at the end of the process. In the present work, we strongly increased the automation level of the pipeline by implementing an artificial neural network enabling unsupervised bioinformatic analysis. We demonstrate the efficiency of this "µIVC-Useq" technology by rapidly identifying a set of sequences readily accepted by a key domain of the light-up RNA aptamer SRB-2. This work not only shed some new light on the way this aptamer can be engineered, but it also allowed us to easily identify new variants with an up-to 10-fold improved performance.
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49
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Hedžet S, Rupnik M, Accetto T. Novel Siphoviridae Bacteriophages Infecting Bacteroides uniformis Contain Diversity Generating Retroelement. Microorganisms 2021; 9:microorganisms9050892. [PMID: 33919474 PMCID: PMC8143477 DOI: 10.3390/microorganisms9050892] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 11/25/2022] Open
Abstract
Intestinal phages are abundant and important components of gut microbiota, yet the isolated and characterized representatives that infect abundant gut bacteria are sparse. Here we describe the isolation of human intestinal phages infecting Bacteroidesuniformis. Bacteroides is one of the most common bacterial groups in the global human gut microbiota; however, to date not many Bacteroides specific phages are known. Phages isolated in this study belong to a novel viral genus, Bacuni, within the Siphoviridae family. Their genomes encode diversity-generating retroelements (DGR), which were shown in other bacteriophages to promote phage adaptation to rapidly changing environmental conditions and to broaden their host range. Three isolated phages showed 99.83% genome identity but one of them infected a distinct B. uniformis strain. The tropism of Bacuni phages appeared to be dependent on the interplay of DGR mediated sequence variations of gene encoding putative phage fimbrial tip proteins and mutations in host genes coding for outer-membrane proteins. We found prophages with up to 85% amino acid similarity over two-thirds of the Bacuni phage genome in the B. acidifaciens and Prevotella sp. genomes. Despite the abundance of Bacteroides within the human microbiome, we found Bacuni phages only in a limited subset of published gut metagenomes.
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Affiliation(s)
- Stina Hedžet
- Centre for Medical Microbiology, Department for Microbiological Research, National Laboratory for Health, Environment and Food (NLZOH), 2000 Maribor, Slovenia; (S.H.); (M.R.)
| | - Maja Rupnik
- Centre for Medical Microbiology, Department for Microbiological Research, National Laboratory for Health, Environment and Food (NLZOH), 2000 Maribor, Slovenia; (S.H.); (M.R.)
- Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
| | - Tomaž Accetto
- Animal Science Department, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
- Correspondence:
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50
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Fremin BJ, Bhatt AS. Comparative genomics identifies thousands of candidate structured RNAs in human microbiomes. Genome Biol 2021; 22:100. [PMID: 33845850 PMCID: PMC8040213 DOI: 10.1186/s13059-021-02319-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 03/19/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Structured RNAs play varied bioregulatory roles within microbes. To date, hundreds of candidate structured RNAs have been predicted using informatic approaches that search for motif structures in genomic sequence data. The human microbiome contains thousands of species and strains of microbes. Yet, much of the metagenomic data from the human microbiome remains unmined for structured RNA motifs primarily due to computational limitations. RESULTS We sought to apply a large-scale, comparative genomics approach to these organisms to identify candidate structured RNAs. With a carefully constructed, though computationally intensive automated analysis, we identify 3161 conserved candidate structured RNAs in intergenic regions, as well as 2022 additional candidate structured RNAs that may overlap coding regions. We validate the RNA expression of 177 of these candidate structures by analyzing small fragment RNA-seq data from four human fecal samples. CONCLUSIONS This approach identifies a wide variety of candidate structured RNAs, including tmRNAs, antitoxins, and likely ribosome protein leaders, from a wide variety of taxa. Overall, our pipeline enables conservative predictions of thousands of novel candidate structured RNAs from human microbiomes.
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Affiliation(s)
- Brayon J Fremin
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - Ami S Bhatt
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA.
- Department of Medicine (Hematology), Stanford University, Stanford, CA, 94305, USA.
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