<p> MauD appears critical to proper formation of the small subunit of methylamine dehydrogenase, which has both an unusual tryptophan tryptophylquinone cofactor and multiple disulphide bonds. MauD shares sequence similarity, including a CPxC motif, with a number of thiol:disulphide interchange proteins. In MauD mutants, the small subunit apparently does not form properly and is rapidly degraded [<cite idref="PUB00013087"/>].</p> Methylamine dehydrogenase accessory protein MauD