Reaction catalyzed by dissimilatory sulfite reductase (1.8.99.5)

	hydrogen sulfide	+		a [DsrC protein]-disulfide	=		a [DsrC protein]-S-sulfanyl-L-cysteine
	hydrogen sulfide	+		a [DsrC protein]-disulfide	=		a [DsrC protein]-S-sulfanyl-L-cysteine