Acetyl-CoA decarbonylase/synthase (ACDS) is a multienzyme complex (carbon monoxide dehydrogenase is a synonym). The ACDS complex carries out an unusual reaction involving the reversible cleavage and synthesis of acetyl-CoA in methanogens. The family contains the 4Fe-4S ferredoxin domain [C-x(2)-C-x(2)-C-x(3)-C-[PEG]] between residues 448-462 of the model. CO dehydrogenase/acetyl-CoA synthase complex alpha subunit