Allows photoautotrophic growth on dimethyl sulfide (DMS) as the sole electron donor. dimethyl sulfide + 2 Fe(III)-[cytochrome c2] + H2O = dimethyl sulfoxide + 2 Fe(II)-[cytochrome c2] + 2 H(+) Binds 1 [4Fe-4S] cluster. Binds 1 molybdenum-bis(molybdopterin guanine dinucleotide) (Mo-bis-MGD) cofactor per subunit. Heterotrimer of alpha, beta and gamma subunits. Predicted to be exported by the Tat system. The position of the signal peptide cleavage has been experimentally proven. Belongs to the prokaryotic molybdopterin-containing oxidoreductase family.