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Moreira S, Chyou TY, Wade J, Brown C. Diversification of the Rho transcription termination factor in bacteria. Nucleic Acids Res 2024; 52:8979-8997. [PMID: 38966992 PMCID: PMC11347177 DOI: 10.1093/nar/gkae582] [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: 10/26/2023] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/06/2024] Open
Abstract
Correct termination of transcription is essential for gene expression. In bacteria, factor-dependent termination relies on the Rho factor, that classically has three conserved domains. Some bacteria also have a functional insertion region. However, the variation in Rho structure among bacteria has not been analyzed in detail. This study determines the distribution, sequence conservation, and predicted features of Rho factors with diverse domain architectures by analyzing 2730 bacterial genomes. About half (49.8%) of the species analyzed have the typical Escherichia coli like Rho while most of the other species (39.8%) have diverse, atypical forms of Rho. Besides conservation of the main domains, we describe a duplicated RNA-binding domain present in specific species and novel variations in the bicyclomycin binding pocket. The additional regions observed in Rho proteins exhibit remarkable diversity. Commonly, however, they have exceptional amino acid compositions and are predicted to be intrinsically disordered, to undergo phase separation, or have prion-like behavior. Phase separation has recently been shown to play roles in Rho function and bacterial fitness during harsh conditions in one species and this study suggests a more widespread role. In conclusion, diverse atypical Rho factors are broadly distributed among bacteria, suggesting additional cellular roles.
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Affiliation(s)
- Sofia M Moreira
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Te-yuan Chyou
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Joseph T Wade
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY 12222, USA
| | - Chris M Brown
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, Otago 9054, New Zealand
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2
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Parize E, Gerhardt EC, Oliveira AC, Pedrosa FO, Souza EM, Huergo LF, Steffens MB. Expression, purification and characterization of the transcription termination factor Rho from Azospirillum brasilense. Protein Expr Purif 2022; 198:106114. [DOI: 10.1016/j.pep.2022.106114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/10/2022] [Accepted: 05/24/2022] [Indexed: 11/25/2022]
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Cryo-EM structure of transcription termination factor Rho from Mycobacterium tuberculosis reveals bicyclomycin resistance mechanism. Commun Biol 2022; 5:120. [PMID: 35140348 PMCID: PMC8828861 DOI: 10.1038/s42003-022-03069-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/21/2022] [Indexed: 01/17/2023] Open
Abstract
The bacterial Rho factor is a ring-shaped motor triggering genome-wide transcription termination and R-loop dissociation. Rho is essential in many species, including in Mycobacterium tuberculosis where rho gene inactivation leads to rapid death. Yet, the M. tuberculosis Rho [MtbRho] factor displays poor NTPase and helicase activities, and resistance to the natural Rho inhibitor bicyclomycin [BCM] that remain unexplained. To address these issues, we solved the cryo-EM structure of MtbRho at 3.3 Å resolution. The MtbRho hexamer is poised into a pre-catalytic, open-ring state wherein specific contacts stabilize ATP in intersubunit ATPase pockets, thereby explaining the cofactor preference of MtbRho. We reveal a leucine-to-methionine substitution that creates a steric bulk in BCM binding cavities near the positions of ATP γ-phosphates, and confers resistance to BCM at the expense of motor efficiency. Our work contributes to explain the unusual features of MtbRho and provides a framework for future antibiotic development. Cryo-EM shows that M. tuberculosis Rho-factor adopts an open, ring-shaped hexamer conformation and a steric bulk in the cavity for bicyclomycin binding, which explains resistance to the antibiotic.
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Simon I, Delaleau M, Schwartz A, Boudvillain M. A Large Insertion Domain in the Rho Factor From a Low G + C, Gram-negative Bacterium is Critical for RNA Binding and Transcription Termination Activity. J Mol Biol 2021; 433:167060. [PMID: 34023400 DOI: 10.1016/j.jmb.2021.167060] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/30/2021] [Accepted: 05/16/2021] [Indexed: 10/21/2022]
Abstract
Rho-dependent termination of transcription (RDTT) is a critical regulatory mechanism specific to bacteria. In a subset of species including most Actinobacteria and Bacteroidetes, the Rho factor contains a large, poorly conserved N-terminal insertion domain (NID) of cryptic function. To date, only two NID-bearing Rho factors from high G + C Actinobacteria have been thoroughly characterized. Both can trigger RDTT at promoter-proximal sites or with structurally constrained transcripts that are unsuitable for the archetypal, NID-less Rho factor of Escherichia coli (EcRho). Here, we provide the first biochemical characterization of a NID-bearing Rho factor from a low G + C bacterium. We show that Bacteroides fragilis Rho (BfRho) is a bona fide RNA-dependent NTPase motor able to unwind long RNA:DNA duplexes and to disrupt transcription complexes. The large NID (~40% of total mass) strongly increases BfRho affinity for RNA, is strictly required for RDTT, but does not promote RDTT at promoter-proximal sites or with a structurally constrained transcript. Furthermore, the NID does not preclude modulation of RDTT by transcription factors NusA and NusG or by the Rho inhibitor bicyclomycin. Although the NID contains a prion-like Q/N-rich motif, it does not spontaneously trigger formation of β-amyloids. Thus, despite its unusually large RNA binding domain, BfRho behaves more like the NID-less EcRho than NID-bearing counterparts from high G + C Actinobacteria. Our data highlight the evolutionary plasticity of Rho's N-terminal region and illustrate how RDTT is adapted to distinct genomic contents.
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Affiliation(s)
- Isabelle Simon
- Centre de Biophysique Moléculaire, CNRS UPR4301, Rue Charles Sadron, 45071 Orléans cedex 2, France; ED 549, Santé, Sciences Biologiques & Chimie du Vivant, Université d'Orléans, France
| | - Mildred Delaleau
- Centre de Biophysique Moléculaire, CNRS UPR4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Annie Schwartz
- Centre de Biophysique Moléculaire, CNRS UPR4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Marc Boudvillain
- Centre de Biophysique Moléculaire, CNRS UPR4301, Rue Charles Sadron, 45071 Orléans cedex 2, France.
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Ray-Soni A, Bellecourt MJ, Landick R. Mechanisms of Bacterial Transcription Termination: All Good Things Must End. Annu Rev Biochem 2016; 85:319-47. [PMID: 27023849 DOI: 10.1146/annurev-biochem-060815-014844] [Citation(s) in RCA: 227] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transcript termination is essential for accurate gene expression and the removal of RNA polymerase (RNAP) at the ends of transcription units. In bacteria, two mechanisms are responsible for proper transcript termination: intrinsic termination and Rho-dependent termination. Intrinsic termination is mediated by signals directly encoded within the DNA template and nascent RNA, whereas Rho-dependent termination relies upon the adenosine triphosphate-dependent RNA translocase Rho, which binds nascent RNA and dissociates the elongation complex. Although significant progress has been made in understanding these pathways, fundamental details remain undetermined. Among those that remain unresolved are the existence of an inactivated intermediate in the intrinsic termination pathway, the role of Rho-RNAP interactions in Rho-dependent termination, and the mechanisms by which accessory factors and nucleoid-associated proteins affect termination. We describe current knowledge, discuss key outstanding questions, and highlight the importance of defining the structural rearrangements of RNAP that are involved in the two mechanisms of transcript termination.
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Affiliation(s)
- Ananya Ray-Soni
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
| | - Michael J Bellecourt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706; , .,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706;
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D'Heygère F, Schwartz A, Coste F, Castaing B, Boudvillain M. ATP-dependent motor activity of the transcription termination factor Rho from Mycobacterium tuberculosis. Nucleic Acids Res 2015; 43:6099-111. [PMID: 25999346 PMCID: PMC4499133 DOI: 10.1093/nar/gkv505] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/04/2015] [Indexed: 11/13/2022] Open
Abstract
The bacterial transcription termination factor Rho-a ring-shaped molecular motor displaying directional, ATP-dependent RNA helicase/translocase activity-is an interesting therapeutic target. Recently, Rho from Mycobacterium tuberculosis (MtbRho) has been proposed to operate by a mechanism uncoupled from molecular motor action, suggesting that the manner used by Rho to dissociate transcriptional complexes is not conserved throughout the bacterial kingdom. Here, however, we demonstrate that MtbRho is a bona fide molecular motor and directional helicase which requires a catalytic site competent for ATP hydrolysis to disrupt RNA duplexes or transcription elongation complexes. Moreover, we show that idiosyncratic features of the MtbRho enzyme are conferred by a large, hydrophilic insertion in its N-terminal 'RNA binding' domain and by a non-canonical R-loop residue in its C-terminal 'motor' domain. We also show that the 'motor' domain of MtbRho has a low apparent affinity for the Rho inhibitor bicyclomycin, thereby contributing to explain why M. tuberculosis is resistant to this drug. Overall, our findings support that, in spite of adjustments of the Rho motor to specific traits of its hosting bacterium, the basic principles of Rho action are conserved across species and could thus constitute pertinent screening criteria in high-throughput searches of new Rho inhibitors.
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Affiliation(s)
- François D'Heygère
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France Ecole doctorale Santé, Sciences Biologiques et Chimie du Vivant (ED 549), Université d'Orléans, Orléans, France
| | - Annie Schwartz
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Franck Coste
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Bertrand Castaing
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France ITP Sciences Biologiques & Chimie du Vivant, Université d'Orléans, Orléans, France
| | - Marc Boudvillain
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France ITP Sciences Biologiques & Chimie du Vivant, Université d'Orléans, Orléans, France
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7
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Soares E, Schwartz A, Nollmann M, Margeat E, Boudvillain M. The RNA-mediated, asymmetric ring regulatory mechanism of the transcription termination Rho helicase decrypted by time-resolved nucleotide analog interference probing (trNAIP). Nucleic Acids Res 2014; 42:9270-84. [PMID: 25016524 PMCID: PMC4132721 DOI: 10.1093/nar/gku595] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rho is a ring-shaped, ATP-dependent RNA helicase/translocase that dissociates transcriptional complexes in bacteria. How RNA recognition is coupled to ATP hydrolysis and translocation in Rho is unclear. Here, we develop and use a new combinatorial approach, called time-resolved Nucleotide Analog Interference Probing (trNAIP), to unmask RNA molecular determinants of catalytic Rho function. We identify a regulatory step in the translocation cycle involving recruitment of the 2′-hydroxyl group of the incoming 3′-RNA nucleotide by a Rho subunit. We propose that this step arises from the intrinsic weakness of one of the subunit interfaces caused by asymmetric, split-ring arrangement of primary RNA tethers around the Rho hexamer. Translocation is at highest stake every seventh nucleotide when the weak interface engages the incoming 3′-RNA nucleotide or breaks, depending on RNA threading constraints in the Rho pore. This substrate-governed, ‘test to run’ iterative mechanism offers a new perspective on how a ring-translocase may function or be regulated. It also illustrates the interest and versatility of the new trNAIP methodology to unveil the molecular mechanisms of complex RNA-based systems.
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Affiliation(s)
- Emilie Soares
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Annie Schwartz
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Marcello Nollmann
- CNRS UMR5048, Universités Montpellier I et II, Centre de Biochimie Structurale, 29 rue de Navacelles, 34090 Montpellier, France INSERM U1054, Montpellier, France
| | - Emmanuel Margeat
- CNRS UMR5048, Universités Montpellier I et II, Centre de Biochimie Structurale, 29 rue de Navacelles, 34090 Montpellier, France INSERM U1054, Montpellier, France
| | - Marc Boudvillain
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France ITP Sciences Biologiques & Chimie du Vivant, Université d'Orléans, France
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8
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D’Heygère F, Rabhi M, Boudvillain M. Phyletic distribution and conservation of the bacterial transcription termination factor Rho. Microbiology (Reading) 2013; 159:1423-1436. [DOI: 10.1099/mic.0.067462-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- François D’Heygère
- Ecole doctorale Santé, Sciences Biologiques et Chimie du Vivant (ED 549), Université d’Orléans, France
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Makhlouf Rabhi
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Marc Boudvillain
- ITP Sciences Biologiques et Chimie du Vivant, Université d’Orléans, France
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, 45071 Orléans cedex 2, France
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9
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Boudvillain M, Figueroa-Bossi N, Bossi L. Terminator still moving forward: expanding roles for Rho factor. Curr Opin Microbiol 2013; 16:118-24. [DOI: 10.1016/j.mib.2012.12.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 12/28/2012] [Accepted: 12/29/2012] [Indexed: 12/29/2022]
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Koslover DJ, Fazal FM, Mooney RA, Landick R, Block SM. Binding and translocation of termination factor rho studied at the single-molecule level. J Mol Biol 2012; 423:664-76. [PMID: 22885804 DOI: 10.1016/j.jmb.2012.07.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/13/2012] [Accepted: 07/27/2012] [Indexed: 12/01/2022]
Abstract
Rho termination factor is an essential hexameric helicase responsible for terminating 20-50% of all mRNA synthesis in Escherichia coli. We used single-molecule force spectroscopy to investigate Rho-RNA binding interactions at the Rho utilization site of the λtR1 terminator. Our results are consistent with Rho complexes adopting two states: one that binds 57 ± 2nt of RNA across all six of the Rho primary binding sites, and another that binds 85 ± 2nt at the six primary sites plus a single secondary site situated at the center of the hexamer. The single-molecule data serve to establish that Rho translocates 5'→3' toward RNA polymerase (RNAP) by a tethered-tracking mechanism, looping out the intervening RNA between the Rho utilization site and RNAP. These findings lead to a general model for Rho binding and translocation and establish a novel experimental approach that should facilitate additional single-molecule studies of RNA-binding proteins.
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Rabhi M, Espéli O, Schwartz A, Cayrol B, Rahmouni AR, Arluison V, Boudvillain M. The Sm-like RNA chaperone Hfq mediates transcription antitermination at Rho-dependent terminators. EMBO J 2011; 30:2805-16. [PMID: 21673658 DOI: 10.1038/emboj.2011.192] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 05/26/2011] [Indexed: 11/09/2022] Open
Abstract
In Escherichia coli, the essential motor protein Rho promotes transcription termination in a tightly controlled manner that is not fully understood. Here, we show that the general post-transcriptional regulatory protein Hfq associates with Rho to regulate Rho function. The Hfq:Rho complex can be further stabilized by RNA bridging both factors in a configuration that inhibits the ATP hydrolysis and duplex unwinding activities of Rho and that mediates transcription antitermination at Rho-dependent terminators in vitro and in vivo. Antitermination at a prototypical terminator (λtR1) requires Hfq binding to an A/U-rich transcript region directly upstream from the terminator. Antitermination is modulated by trans-acting factors (NusG or nucleic acid competitors) that affect Hfq association with Rho or RNA. These data unveil a new Hfq function and a novel transcription regulatory mechanism with potentially important implications for bacterial RNA metabolism, gene silencing, and pathogenicity.
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Affiliation(s)
- Makhlouf Rabhi
- Centre de Biophysique Moléculaire, CNRS UPR4301, rue Charles Sadron, Orléans Cedex 2, France
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