Probably has no xanthine dehydrogenase activity; however deletion results in increased adenine sensitivity, suggesting that this protein contributes to the conversion of adenine to guanine nucleotides during purine salvage. Binds 2 [2Fe-2S] centers. Binds 1 Mo-molybdopterin (Mo-MPT) cofactor per subunit. Belongs to the xanthine dehydrogenase family.