Escherichia coli DsbD

Abstract DsbA, DsbC periplasmic proteins of Escherichia coli (see entries pp. 318, 324) are two key players involved in disulfide bond formation. DsbA has been shown to act as an oxidase (Wunderlich, Glockshuber, 1993; Zapun et al., 1993), DsbC exhibits the dual properties of an oxidase, an isomerase (Zapun et al., 1995). These findings suggested that a reductase activity could also be required in the bacterial periplasm to facilitate disulfide bond rearrangement, some specific processes requiring reduced cysteines. Isolation of extragenic suppressors of dsbA null mutants led to the identification of such a putative activity encoded by a gene designated as dsbD (Missiakas etal., 1995).