Protein
Ni-sirohydrochlorin a,c-diamide reductive cyclase complex, component CfbD
Organism
Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)
Function
Involved in the biosynthesis of the unique nickel-containing tetrapyrrole coenzyme F430, the prosthetic group of methyl-coenzyme M reductase (MCR), which plays a key role in methanogenesis and anaerobic methane oxidation. Catalyzes both the six-electron reduction of the tetrahydroporphyrin ring system and the gamma-lactamization of the c-acetamide side chain of Ni-sirohydrochlorin a,c-diamide to yield 15,17(3)-seco-F430-17(3)-acid (seco-F430), the last intermediate in the biosynthesis of the coenzyme F430.
Similarity
Belongs to the NifD/NifK/NifE/NifN family.
Sequence
MHPRPSPIAASLYTLRDLDADVIILHGPHGCCFRTGRLLETDGVRVLTTAMSEQDFIFGASDKLTETLRKAYEMFSPKLVGVVGTCASMIIGEDLKEAVQRAGIPARVLAVESHGGFGEGDNTEGAIIVLEAAAEQGIIPEEEAERQIKMLKLATEIEKTRGMAQGKYIRPSYGDDKDEVALRVLEAIMEGRRVAFVLNAKKETSYLFADTLTLPFGSLNPDNPPIIIANLDKGIGLPRIRRHAENILSEIERSGNRVEHITGGLDEYPITGARAAEILRNEEIEFAVVSGVPHALPVEELGLESVAVTDGPRLVEPLRGLGYTHVVAELDAHARTLGQRSIVESDFGDALRRNIKKVI