This domain is found in various molybdopterin - containing oxidoreductases and tungsten formylmethanofuran dehydrogenase subunit d (FwdD) and molybdenum formylmethanofuran dehydrogenase subunit (FmdD); where the domain constitutes almost the entiresubunit. The formylmethanofuran dehydrogenase catalyses thefirst step in methane formation from CO2 in methanogenic archaeaand has a molybdopterin dinucleotide cofactor [1]. This domaincorresponds to the C-terminal domain IV in dimethyl sulfoxide(DMSO)reductase which interacts with the 2-amino pyrimidone ringof both molybdopterin guanine dinucleotide molecules [2]. Molydopterin dinucleotide binding domain Molydop_binding