May be involved in the biosynthesis of molybdopterin. Can bind GTP and has low GTPase activity. Can bind MPT, but has no MPT adenylyl transferase activity. Cofactor biosynthesis; molybdopterin biosynthesis. Homohexamer. Dimer of trimers. By anaerobiosis, repressed by the molybdenum cofactor. Belongs to the MoaB/Mog family.