title: Coordinate positive regulation of genes encoding [NiFe] hydrogenases in Methanococcus voltae.
abstract: Two transcription units encoding selenium-free [NiFe] hydrogenases in Methanococcus voltae are transcribed only upon selenium deprivation. Their products replace or complement selenocysteine-containing isoenzymes. The transcription units are linked by a 453-bp intergenic region, and are subject to both positive and negative transcriptional regulation. The mechanism of positive regulation was studied in detail. Mutations in identical 11-bp putative activator recognition sites close to each promoter showed that each site is involved in the activation of both promoters. Sequence-specific DNA-affinity chromatography yielded a 55-kDa protein which specifically recognized the 11-bp sequence. We consider this protein to be a transcriptional activator for both transcription units.
authors.affiliation: Department of Biology, Philipps-University Marburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Klein
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D019848:Gene Expression Regulation, Archaeal; D015971:Gene Expression Regulation, Enzymologic; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D006864:Hydrogenase / Q000235:genetics*; D007438:Introns; D007527:Isoenzymes / Q000235:genetics; D017017:Methanococcus / Q000235:genetics*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D015183:Restriction Mapping; D012643:Selenium / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D007527:Isoenzymes; C043296:nickel-iron hydrogenase; D006864:Hydrogenase; D005966:Glucuronidase; D012643:Selenium