<p>Many bacterial species are capable of anaerobic growth by using dimethylsulphoxide (DMSO) as the terminal electron acceptor, with DMSO reductase as the terminal elctron transfer enzyme. In <taxon tax_id="562">Escherichia coli</taxon> and many other Gram-negative bacteria DMSO reductase is a membrane-bound enzyme composed of three subunits; a catalytic molybdenum-containing subunit (DmsA), an electron transfer subunit containing a [4Fe-4S] cluster (DmsB), and a hydrophobic membrane-spanning anchor subunit which attaches the enzyme to the cytoplasmic membrane (DmsC) [<cite idref="PUB00034652"/>, <cite idref="PUB00028090"/>]. It is generally thought now that DmsAB faces the periplasm, contradicting previous results suggesting a cytoplasmic location. The N-terminal region of DmsA contains a "twin-arginine" signal sequence, suggesting export to the periplasm occurs via the TAT secretion pathway.</p><p>This entry represents known and predicted bacterial DmsA polypeptides. Several species contain one or more paralogs of DmsA. In <i>E. coli</i>, the two paralogs of DmsA, YnfE and YnfF, are encoded within the ynfEFGHI operon [<cite idref="PUB00034653"/>]. YnfE and YnfF cannot form a functional complex with DmsBC, but YnfFGH can restore growth on DMSO when DmABC is deleted. The function of YnfE is not known and it appears to prevent formation of the YnfFGH complex if present.</p>