title: Transcriptional and posttranscriptional events control copper-responsive expression of a Rhodobacter capsulatus multicopper oxidase.
abstract: The copper-regulated Rhodobacter capsulatus cutO (multicopper oxidase) gene confers copper tolerance and is carried in the tricistronic orf635-cutO-cutR operon. Transcription of cutO strictly depends on the promoter upstream of orf635, as demonstrated by lacZ reporter fusions to nested promoter fragments. Remarkably, orf635 expression was not affected by copper availability, whereas cutO and cutR were expressed only in the presence of copper. Differential regulation was abolished by site-directed mutations within the orf635-cutO intergenic region, suggesting that this region encodes a copper-responsive mRNA element. Bioinformatic predictions and RNA structure probing experiments revealed an intergenic stem-loop structure as the candidate mRNA element. This is the first posttranscriptional copper response mechanism reported in bacteria.
authors.affiliation: Biologie der Mikroorganismen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, Bochum, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Rademacher
authors.forename: Roman
authors.initials: R
authors.lastname: Moser
authors.forename: Jan-Wilm
authors.initials: JW
authors.lastname: Lackmann
authors.forename: Birgit
authors.initials: B
authors.lastname: Klinkert
authors.forename: Franz
authors.initials: F
authors.lastname: Narberhaus
authors.forename: Bernd
authors.initials: B
authors.lastname: Masepohl
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000494:pharmacology*; D021901:DNA, Intergenic; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D009876:Operon; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D012329:RNA, Bacterial; D016354:Rhodobacter capsulatus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D001426:Bacterial Proteins; D021901:DNA, Intergenic; D012329:RNA, Bacterial; D003300:Copper; D010088:Oxidoreductases