title: A hydrogen-sensing multiprotein complex controls aerobic hydrogen metabolism in Ralstonia eutropha.
abstract: H(2) is an attractive energy source for many microorganisms and is mostly consumed before it enters oxic habitats. Thus aerobic H(2)-oxidizing organisms receive H(2) only occasionally and in limited amounts. Metabolic adaptation requires a robust oxygen-tolerant hydrogenase enzyme system and special regulatory devices that enable the organism to respond rapidly to a changing supply of H(2). The proteobacterium Ralstonia eutropha strain H16 that harbours three [NiFe] hydrogenases perfectly meets these demands. The unusual biochemical and structural properties of the hydrogenases are described, including the strategies that confer O(2) tolerance to the NAD-reducing soluble hydrogenase and the H(2)-sensing regulatory hydrogenase. The regulatory hydrogenase that forms a complex with a histidine protein kinase recognizes H(2) in the environment and transmits the signal to a response regulator, which in turn controls transcription of the hydrogenase genes.
authors.affiliation: Institute of Biology, Humboldt University, Berlin, Germany. baerbel.friedrich@rz.hu-berlin.de
authors.forename: B
authors.initials: B
authors.lastname: Friedrich
authors.forename: T
authors.initials: T
authors.lastname: Buhrke
authors.forename: T
authors.initials: T
authors.lastname: Burgdorf
authors.forename: O
authors.initials: O
authors.lastname: Lenz
mesh_terms: D000332:Aerobiosis; D020118:Cupriavidus necator / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000235:genetics; D005810:Multigene Family; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D006859:Hydrogen; D006864:Hydrogenase