title: cAMP receptor protein (CRP) positively regulates the yihU-yshA operon in Salmonella enterica serovar Typhi.
abstract: Salmonella enterica serovar Typhi (S. Typhi) is the aetiological agent of typhoid fever in humans. This bacterium is also able to persist in its host, causing a chronic disease by colonizing the spleen, liver and gallbladder, in the last of which the pathogen forms biofilms in order to survive the bile. Several genetic components, including the yihU-yshA genes, have been suggested to be involved in the survival of Salmonella in the gallbladder. In this work we describe how the yihU-yshA gene cluster forms a transcriptional unit regulated positively by the cAMP receptor global regulator CRP (cAMP receptor protein). The results obtained show that two CRP-binding sites on the regulatory region of the yihU-yshA operon are required to promote transcriptional activation. In this work we also demonstrate that the yihU-yshA transcriptional unit is carbon catabolite-repressed in Salmonella, indicating that it forms part of the CRP regulon in enteric bacteria.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: J M
authors.initials: JM
authors.lastname: Villarreal
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: I
authors.initials: I
authors.lastname: Hernández-Lucas
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: F
authors.initials: F
authors.lastname: Gil
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: I L
authors.initials: IL
authors.lastname: Calderón
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Calva
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: C P
authors.initials: CP
authors.lastname: Saavedra
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D057465:Catabolite Repression; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D006884:Hydroxybutyrate Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009876:Operon; D012485:Salmonella typhi / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D014435:Typhoid Fever / Q000382:microbiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D006884:Hydroxybutyrate Dehydrogenase