title: Characterization of the small untranslated RNA RyhB and its regulon in Vibrio cholerae.
abstract: Numerous small untranslated RNAs (sRNAs) have been identified in Escherichia coli in recent years, and their roles are gradually being defined. However, few of these sRNAs appear to be conserved in Vibrio cholerae, and both identification and characterization of sRNAs in V. cholerae remain at a preliminary stage. We have characterized one of the few sRNAs conserved between E. coli and V. cholerae: RyhB. Sequence conservation is limited to the central region of the gene, and RyhB in V. cholerae is significantly larger than in E. coli. As in E. coli, V. cholerae RyhB is regulated by the iron-dependent repressor Fur, and it interacts with the RNA-binding protein Hfq. The regulons controlled by RyhB in V. cholerae and E. coli appear to differ, although some overlap is evident. Analysis of gene expression in V. cholerae in the absence of RyhB suggests that the role of this sRNA is not limited to control of iron utilization. Quantitation of RyhB expression in the suckling mouse intestine suggests that iron availability is not limiting in this environment, and RyhB is not required for colonization of this mammalian host by V. cholerae.
authors.affiliation: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111, USA. brigid.davis@tufts.edu
authors.forename: Brigid M
authors.initials: BM
authors.lastname: Davis
authors.forename: Mariam
authors.initials: M
authors.lastname: Quinones
authors.forename: Jason
authors.initials: J
authors.lastname: Pratt
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Ding
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Waldor
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D012329:RNA, Bacterial; D022661:RNA, Untranslated; D018085:Regulon; D014734:Vibrio cholerae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D022661:RNA, Untranslated; D007501:Iron