title: Active Site of the NAD(+)-Reducing Hydrogenase from Ralstonia eutropha Studied by EPR Spectroscopy.
abstract: Pulsed ENDOR and HYSCORE measurements were carried out to characterize the active site of the oxygen-tolerant NAD(+)-reducing hydrogenase of Ralstonia eutropha. The catalytically active Nia-C state exhibits a bridging hydride between iron and nickel in the active site, which is photodissociated upon illumination. Its hyperfine coupling is comparable to that of standard hydrogenases. In addition, a histidine residue could be identified, which shows hyperfine and nuclear quadrupole parameters in significant variance from comparable histidine residues that are conserved in standard [NiFe] hydrogenases, and might be related to the O2 tolerance of the enzyme.
authors.affiliation: Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Löwenstein
authors.affiliation: Institut für Chemie, Sekr. PC14, Technische Universität Berlin , Strasse des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Lauterbach
authors.affiliation: Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Teutloff
authors.affiliation: Institut für Chemie, Sekr. PC14, Technische Universität Berlin , Strasse des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Lenz
authors.affiliation: Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Bittl
mesh_terms: D020134:Catalytic Domain; D020118:Cupriavidus necator / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism*; D009243:NAD / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D009243:NAD; D006864:Hydrogenase