InterPro domain: IPR006657

This domain is found in various molybdopterin-containing oxidoreductases, tungsten formylmethanofuran dehydrogenase subunit d (FwdD) and molybdenum formylmethanofuran dehydrogenase subunit (FmdD), where the domain constitutes almost the entire subunit. The formylmethanofuran dehydrogenase catalyses the first step in methane formation from CO2 in methanogenic archaea and has a molybdopterin dinucleotide cofactor [ 1 ]. This domain corresponds to the C-terminal domain IV in dimethyl sulfoxide (DMSO) reductase which interacts with the 2-amino pyrimidone ring of both molybdopterin guanine dinucleotide molecules [ 2 ].

1. The formylmethanofuran dehydrogenase isoenzymes in Methanobacterium wolfei and Methanobacterium thermoautotrophicum: induction of the molybdenum isoenzyme by molybdate and constitutive synthesis of the tungsten isoenzyme. Arch. Microbiol. 170, 389-93
2. Crystal structure of dimethyl sulfoxide reductase from Rhodobacter capsulatus at 1.88 A resolution. J. Mol. Biol. 263, 53-69