The enzyme is part of the Sox enzyme system, which participates in a bacterial thiosulfate oxidation pathway that produces sulfate. It catalyses two reactions in the pathway – early in the pathway it attaches a thiosulfate molecule to the sulfur atom of an?L-cysteine of a SoxY protein; later it transfers a second thiosulfate molecule to a sulfane group that is already attached to the same cysteine residue.
