title: Transcriptional regulation of the assT-dsbL-dsbI gene cluster in Salmonella enterica serovar Typhi IMSS-1 depends on LeuO, H-NS, and specific growth conditions.
abstract: The assT gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In Salmonella enterica serovar Typhi IMSS-1, the assT gene is located upstream of the dsbL and dsbI genes, which are involved in a disulfide bond formation required for its activation. The assT-dsbL-dsbI gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned leuO and in a ΔleuO background, two transcription start sites were detected for assT and two for dsbL-dsbI in minimal medium. The H-NS nucleoid protein repressed the expression of the assT-dsbL-dsbI LeuO-dependent operon, as well as of the assT transcriptional units. Thus, the expression of the assT-dsbL-dsbI gene cluster depends on the global regulatory proteins LeuO and H-NS, as well as on specific growth conditions.
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
authors.forename: A L
authors.initials: AL
authors.lastname: Gallego-Hernández
authors.forename: I
authors.initials: I
authors.lastname: Hernández-Lucas
authors.forename: M A
authors.initials: MA
authors.lastname: De la Cruz
authors.forename: L
authors.initials: L
authors.lastname: Olvera
authors.forename: E
authors.initials: E
authors.lastname: Morett
authors.forename: L
authors.initials: L
authors.lastname: Medina-Aparicio
authors.forename: J A
authors.initials: JA
authors.lastname: Ramírez-Trujillo
authors.forename: A
authors.initials: A
authors.lastname: Vázquez
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Mora
authors.forename: E
authors.initials: E
authors.lastname: Calva
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D016680:Genome, Bacterial; D005810:Multigene Family; D009154:Mutation; D009876:Operon; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics; D012485:Salmonella typhi / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D014157:Transcription Factors; C073470:LysR protein, Bacteria; D010088:Oxidoreductases