CODH oxidizes carbon monoxide coupled, via CooF, to the reduction of a hydrogen cation by a hydrogenase (possibly CooH). CO + H2O + 2 oxidized [2Fe-2S]-[ferredoxin] = CO2 + 2 H(+) + 2 reduced [2Fe-2S]-[ferredoxin] Binds 3 [4Fe-4S] clusters per homodimer. Binds 2 [Ni-4Fe-5S] clusters per homodimer. Inactivated by O(2). Homodimer. Loosely attached to the membrane, probably via CooF. Cluster B is an all-cysteinyl-liganded 4Fe-4S cluster; cluster C is a mixed Ni-Fe-S cluster which is the active site of CO oxidation. Cluster D is also an all-cysteinyl-liganded 4Fe-4S cluster that bridges the two subunits of the CODH dimer. Belongs to the Ni-containing carbon monoxide dehydrogenase family.