Expression and Purification of Epidermal Cell Differentiation Inhibitor (EDIN) fromBacillus subtilis

The expression of staphylococcal epidermal cell differentiation inhibitor (EDIN), an ADP-ribosyltransferase targeting the small GTP-binding protein rho p21, was examined usingBacillus subtilis.A recombinant plasmid, containingB. licheniformisα-amylase promoter flanking either a β-glucanase or aB. cereussphingomyelinase signal sequence, and a DNA fragment corresponding to mature EDIN were constructed and used to transformB. subtilisKN2. Transformants were designated ED7 and ED8, respectively. ED7 extracellularly produced recombinant protein, which was purified to homogeneity through column chromatography using SP-Toyopearl 650 cation-exchange gel and the HA1000 hydroxyapatite HPLC column. ED8 did not grow in broth culture. Biochemical and biological studies of purified protein revealed that ED7 produced a correctly processed recombinant EDIN, indistinguishable from natural EDIN.