title: Involvement of histidine residues in the catalytic mechanism of hydrogenases.
abstract: In spite of their structural and amino acid sequence differences, Fe-only and Ni-containing hydrogenases achieved the same catalytic reactions. A chemical modification of histidine residues using a highly specific reagent (pentaammineruthenium II) has been carried out on Desulfovibrio vulgaris Hildenborough Fe-hydrogenase and Desulfovibrio desulfuricans Norway Ni-Fe-Se-hydrogenase. The preliminary results obtained suggest the existence of a general mechanism involving histidine residues in the two groups of hydrogenases. These residues may be part of the histidine-containing motive shown to be present in both Fe- and Ni-Fe-hydrogenase sequences by Hydrophobic Cluster Analysis. This analysis also allows us to suggest a functional role for the small subunit of Desulfovibrio vulgaris Hildenborough Fe-hydrogenase.
authors.affiliation: Laboratoire de Chimie Bactérienne, Centre National de la Recherche Scientifique (CNRS), Marseille, France.
authors.forename: I
authors.initials: I
authors.lastname: Mus-Veteau
authors.forename: F
authors.initials: F
authors.lastname: Guerlesquin
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003901:Desulfovibrio / Q000201:enzymology; D006639:Histidine / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006864:Hydrogenase / Q000737:chemistry*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D006639:Histidine; C058560:nickel-iron-selenium hydrogenase; D006864:Hydrogenase