SERINE-PROTEASE EPIP FROM STAPHYLOCOCCUS-EPIDERMIDIS CATALYZES THE PROCESSING OF THE EPIDERMIN PRECURSOR PEPTIDE

The function of serine protease EpiP in epidermin biosynthesis was inv estigated. Epidermin is synthesized as a 52-amino-acid precursor pepti de, EpiA, which is posttranslationally modified and processed to the m ature 22-amino acid peptide antibiotic, epiP was expressed in Staphylo coccus carnosus with xylose-regulated expression vector pCX15, The cle avage of the unmodified EpiA precursor peptide to leader peptide and p roepidermin by EpiP-containing culture filtrates of S. carnosus (pCX15 epiP) was followed by reversed-phase chromatography and subsequent ele ctrospray mass spectrometry.