title: Regulation of the expression of the Acidithiobacillus ferrooxidans rus operon encoding two cytochromes c, a cytochrome oxidase and rusticyanin.
abstract: The regulation of the expression of the rus operon, proposed to encode an electron transfer chain from the outer to the inner membrane in the obligate acidophilic chemolithoautroph Acidithiobacillus ferrooxidans, has been studied at the RNA and protein levels. As observed by Northern hybridization, real-time PCR and reverse transcription analyses, this operon was more highly expressed in ferrous iron- than in sulfur-grown cells. Furthermore, it was shown by immunodetection that components of this respiratory chain are synthesized in ferrous iron- rather than in sulfur-growth conditions. Nonetheless, weak transcription and translation products of the rus operon were detected in sulfur-grown cells at the early exponential phase. The results strongly support the notion that rus-operon expression is induced by ferrous iron, in agreement with the involvement of the rus-operon-encoded products in the oxidation of ferrous iron, and that ferrous iron is used in preference to sulfur.
authors.affiliation: Laboratorio de Organización y Expresión del Gen, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela.
authors.forename: Andrés
authors.initials: A
authors.lastname: Yarzábal
authors.affiliation: Laboratoire de Chimie Bactérienne, CNRS, IBSM, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Appia-Ayme
authors.affiliation: Laboratoire de Chimie Bactérienne, CNRS, IBSM, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Jeanine
authors.initials: J
authors.lastname: Ratouchniak
authors.affiliation: Laboratoire de Chimie Bactérienne, CNRS, IBSM, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Violaine
authors.initials: V
authors.lastname: Bonnefoy
mesh_terms: D042763:Acidithiobacillus / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D001400:Azurin / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003574:Cytochrome c Group / Q000235:genetics / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D005786:Gene Expression Regulation; D007501:Iron / Q000378:metabolism; D009876:Operon; D010084:Oxidation-Reduction
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D005296:Ferrous Compounds; C012543:rusticyanin; D001400:Azurin; D007501:Iron; D003576:Electron Transport Complex IV