Biochemical characterization of the HydE and HydG iron-only hydrogenase maturation enzymes from Thermatoga maritima.
Fe-only hydrogenases contain a di-iron active site complex, in which the two Fe atoms have carbon monoxide and cyanide ligands and are linked together by a putative di(thiomethyl)amine molecule. We have cloned, purified and characterized the HydE and HydG proteins, thought to be involved in the biosynthesis of this peculiar metal site, from the thermophilic organism Thermotoga maritima. The HydE protein anaerobically reconstituted with iron and sulfide binds two [4Fe-4S] clusters, as characterized by UV and EPR spectroscopy. The HydG protein binds one [4Fe-4S] cluster, and probably an additional one. Both enzymes are able to reductively cleave S-adenosylmethionine (SAM) when reduced by dithionite, confirming that they are Radical-SAM enzymes.
Rubach
Jon K
JK
Laboratoire de Chimie et Biochimie des Centres Rédox Biologiques, UMR 5047, Département Réponses et Dynamiques Cellulaires, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble Cedex 9, France.
Brazzolotto
Xavier
X
Gaillard
Jacques
J
Fontecave
Marc
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D029968:Escherichia coli Proteins / Q000378:metabolism; D006864:Hydrogenase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism; D016415:Sequence Alignment; D013455:Sulfur / Q000378:metabolism; D020124:Thermotoga maritima / Q000201:enzymology*; D015534:Trans-Activators / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; C423908:zraR protein, E coli; D013455:Sulfur; D012436:S-Adenosylmethionine; D007501:Iron; C118830:iron hydrogenase; D006864:Hydrogenase