title: The role of the maturase HydG in [FeFe]-hydrogenase active site synthesis and assembly.
abstract: [FeFe]-hydrogenases catalyze the protons/hydrogen interconversion through a unique di-iron active site consisting of three CO and two CN ligands, and a non-protein SCH(2)XCH(2)S (X=N or O) dithiolate bridge. Site assembly requires two "Radical-S-adenosylmethionine (SAM or AdoMet)" iron-sulfur enzymes, HydE and HydG, and one GTPase, HydF. The sequence homology between HydG and ThiH, a Radical-SAM enzyme which cleaves tyrosine into p-cresol and dehydroglycine, and the finding of a similar cleavage reaction catalyzed by HydG suggests a mechanism for hydrogenase maturation. Here we propose that HydG is specifically involved in the synthesis of the dithiolate ligand, with two tyrosine-derived dehydroglycines as precursors along with an [FeS] cluster of HydG functioning both as electron shuttle and source of the sulfur atoms.
authors.affiliation: Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, UMR 5249-CNRS, IRTSV/CEA-Grenoble, Grenoble Cedex, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Pilet
authors.forename: Yvain
authors.initials: Y
authors.lastname: Nicolet
authors.forename: Carole
authors.initials: C
authors.lastname: Mathevon
authors.forename: Thierry
authors.initials: T
authors.lastname: Douki
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fontecilla-Camps
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis; D020134:Catalytic Domain; D004722:Endoribonucleases / Q000737:chemistry / Q000378:metabolism*; D006864:Hydrogenase / Q000737:chemistry / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D008024:Ligands; C118830:iron hydrogenase; D006864:Hydrogenase; D009713:Nucleotidyltransferases; D004722:Endoribonucleases