The interplay between the disulfide bond formation pathway and cytochrome c maturation in Escherichia coli

► The role of DsbA and DsbD in cytochrome c maturation in E. coli was probed. ► DsbA is not essential for holocytochrome c production. ► DsbD is important but not essential for cytochrome c maturation. ► A model is proposed for cytochrome c biosynthesis in the periplasm of E. coli. ► Heme attachment to and oxidation of the apocytochrome are competing processes.