title: Characterization of the active site of a hydrogen sensor from Alcaligenes eutrophus.
abstract: A third hydrogenase was recently identified in the proteobacterium Alcaligenes eutrophus as a constituent of a novel H2-sensing multicomponent regulatory system. This regulatory hydrogenase (RH) has been overexpressed in cells deficient in both the NAD+-reducing [NiFe]-hydrogenase and the membrane-bound [NiFe]-hydrogenase. EPR, FTIR and activity studies of membrane-free extracts revealed that the RH has an active site much like that of standard [NiFe]-hydrogenases, i.e. a Ni-Fe site with two CN- groups and one CO molecule. Its catalytic power is low, but the RH is always active, insensitive to oxygen, and occurs in only two redox states.
authors.affiliation: E.C. Slater Institute, Biochemistry, University of Amsterdam, The Netherlands.
authors.forename: A J
authors.initials: AJ
authors.lastname: Pierik
authors.forename: M
authors.initials: M
authors.lastname: Schmelz
authors.forename: O
authors.initials: O
authors.lastname: Lenz
authors.forename: B
authors.initials: B
authors.lastname: Friedrich
authors.forename: S P
authors.initials: SP
authors.lastname: Albracht
mesh_terms: D001665:Binding Sites; D002245:Carbon Dioxide / Q000032:analysis; D020118:Cupriavidus necator / Q000378:metabolism*; D003486:Cyanides / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy; D006859:Hydrogen / Q000378:metabolism; D006864:Hydrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013045:Species Specificity; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003486:Cyanides; D011993:Recombinant Fusion Proteins; D002245:Carbon Dioxide; D006859:Hydrogen; C043296:nickel-iron hydrogenase; D006864:Hydrogenase