title: Solution structure of the carbon storage regulator protein CsrA from Escherichia coli.
abstract: The carbon storage regulator A (CsrA) is a protein responsible for the repression of a variety of stationary-phase genes in bacteria. In this work, we describe the nuclear magnetic resonance (NMR)-based structure of the CsrA dimer and its RNA-binding properties. CsrA is a dimer of two identical subunits, each composed of five strands, a small alpha-helix and a flexible C terminus. NMR titration experiments suggest that the beta1-beta2 and beta3-beta4 loops and the C-terminal helix are important elements in RNA binding. Even though the beta3-beta4 loop contains a highly conserved RNA-binding motif, GxxG, typical of KH domains, our structure excludes CsrA from being a member of this protein family, as previously suggested. A mechanism for the recognition of mRNAs downregulated by CsrA is proposed.
authors.affiliation: Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gutiérrez
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Osborne
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Pomerantseva
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Kalle
authors.initials: K
authors.lastname: Gehring
mesh_terms: D000595:Amino Acid Sequence; D002244:Carbon / Q000378:metabolism; D019281:Dimerization; D004563:Electrochemistry; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000502:physiology; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: C093587:CsrA protein, E coli; D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D002244:Carbon