Nature 390, 364–370; (1997)

The pathway for sulphate reduction is incorrect as published: in Fig. 3 on page 367, adenylyl sulphate 3-phosphotransferase (cysC) is not needed in the pathway as outlined, as adenylyl sulphate reductase (aprAB) catalyses the first step in the reduction of adenylyl sulphate. The correct sequence of reactions is: sulphate is first activated to adenylyl sulphate, then reduced to sulphite and subsequently to sulphide. The enzymes catalysing these reactions are: sulphate adenylyltransferase (sat), adenylylsulphate reductase (aprAB), and sulphite reductase (dsrABD). We thank Jens-Dirk Schwenn for bringing this error to our attention.