title: RNA remodeling by bacterial global regulator CsrA promotes Rho-dependent transcription termination.
abstract: RNA-binding protein CsrA is a key regulator of a variety of cellular processes in bacteria, including carbon and stationary phase metabolism, biofilm formation, quorum sensing, and virulence gene expression in pathogens. CsrA binds to bipartite sequence elements at or near the ribosome loading site in messenger RNA (mRNA), most often inhibiting translation initiation. Here we describe an alternative novel mechanism through which CsrA achieves negative regulation. We show that CsrA binding to the upstream portion of the 5' untranslated region of Escherichia coli pgaA mRNA-encoding a polysaccharide adhesin export protein-unfolds a secondary structure that sequesters an entry site for transcription termination factor Rho, resulting in the premature stop of transcription. These findings establish a new paradigm for bacterial gene regulation in which remodeling of the nascent transcript by a regulatory protein promotes Rho-dependent transcription attenuation.
authors.affiliation: CNRS UPR3404, Centre de Génétique Moléculaire, Gif-sur-Yvette 91198, France, affilié à l'Université Paris Sud XI, Orsay 91405, France;
authors.forename: Nara
authors.initials: N
authors.lastname: Figueroa-Bossi
authors.affiliation: CNRS UPR4301, Centre de Biophysique Moléculaire, Orléans 45071, France, affilié à l'Université d'Orléans, Orléans 45100, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Schwartz
authors.affiliation: CNRS UPR3404, Centre de Génétique Moléculaire, Gif-sur-Yvette 91198, France, affilié à l'Université Paris Sud XI, Orsay 91405, France;
authors.forename: Benoit
authors.initials: B
authors.lastname: Guillemardet
authors.affiliation: CNRS UPR4301, Centre de Biophysique Moléculaire, Orléans 45071, France, affilié à l'Université d'Orléans, Orléans 45100, France.
authors.forename: François
authors.initials: F
authors.lastname: D'Heygère
authors.affiliation: CNRS UPR3404, Centre de Génétique Moléculaire, Gif-sur-Yvette 91198, France, affilié à l'Université Paris Sud XI, Orsay 91405, France;
authors.forename: Lionello
authors.initials: L
authors.lastname: Bossi
authors.affiliation: CNRS UPR4301, Centre de Biophysique Moléculaire, Orléans 45071, France, affilié à l'Université d'Orléans, Orléans 45100, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Boudvillain
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D012234:Rho Factor / Q000378:metabolism*; D019779:Salmonella enterica / Q000235:genetics* / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012234:Rho Factor; C582298:pgaA protein, E coli
keywords: CsrA; Rho factor; bacterial gene regulation; transcription attenuation