RNA remodeling by bacterial global regulator CsrA promotes Rho-dependent transcription termination

• Published in: Genes & development Vol. 28; no. 11; pp. 1239 - 1251
• Main Authors: Figueroa-Bossi, Nara, Schwartz, Annie, Guillemardet, Benoit, D'Heygère, François, Bossi, Lionello, Boudvillain, Marc
• Format: Journal Article
• Language: English
• Published: United States Cold Spring Harbor Laboratory Press 01.06.2014
• Subjects: 5' Untranslated Regions - genetics; Bacteria; Bacterial Outer Membrane Proteins - metabolism; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biochemistry, Molecular Biology; Escherichia; Escherichia coli - genetics; Escherichia coli Proteins - metabolism; Gene Expression Regulation, Bacterial; Genomics; Life Sciences; Microbiology and Parasitology; Molecular Sequence Data; Protein Binding; Protein Structure, Secondary; Research Paper; Rho Factor - metabolism; RNA, Bacterial - chemistry; RNA, Bacterial - metabolism; RNA, Messenger - metabolism; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - metabolism; Salmonella enterica - genetics; Salmonella enterica - metabolism; bacterial gene regulation; transcription attenuation; Rho factor; CsrA
• ISSN: 0890-9369; 1549-5477
• DOI: 10.1101/gad.240192.114

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.