title: Regulation of bacterial methane oxidation: transcription of the soluble methane mono-oxygenase operon of Methylococcus capsulatus (Bath) is repressed by copper ions.
abstract: Methane is oxidized to methanol by the enzyme methane mono-oxygenase (MMO) in methanotrophic bacteria. In previous work, this multicomponent enzyme system has been extensively characterized at the biochemical and molecular level. Copper ions have been shown to irreversibly inhibit MMO activity in vivo and in vitro, but the effect of copper ions on transcription of the genes encoding the soluble (cytoplasmic) MMO (sMMO) has not previously been investigated. To examine more closely the regulation of bacterial methane oxidation and to determine the role of copper in this process, we have investigated transcriptional regulation of the sMMO gene cluster in the methanotrophic bacterium Methylococcus capsulatus (Bath). Using Northern blot analysis and primer extension experiments, it was shown that the six ORFs of the sMMO gene cluster are organized as an operon and the transcripts produced upon expression of this operon have been identified. The synthesis of these transcripts was under control of a single copper-regulated promoter, which is as yet not precisely defined.
authors.affiliation: Department of Molecular Biology, Odense University, DK-5230 Odense M, Denmark.
authors.forename: Allan K
authors.initials: AK
authors.lastname: Nielsen
authors.affiliation: Department of Molecular Biology, Odense University, DK-5230 Odense M, Denmark.
authors.forename: Kenn
authors.initials: K
authors.lastname: Gerdes
authors.affiliation: Department of Biochemistry, Odense University, DK-5230 Odense M, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Degn
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Murrell J
authors.initials: MJ
authors.lastname: Colin
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D003300:Copper / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008697:Methane / Q000378:metabolism*; D008772:Methylococcaceae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism*; D009876:Operon; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000096:biosynthesis / Q000235:genetics*; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D012329:RNA, Bacterial; D012333:RNA, Messenger; D003300:Copper; D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane