PRODUCER SELF-PROTECTION AGAINST THE LANTIBIOTIC EPIDERMIN BY THE ABCTRANSPORTER EPIFEG OF STAPHYLOCOCCUS-EPIDERMIDIS TU3298

Self-protection of the epidermin-producing strain Staphylococcus epide rmidis Tu3298 against the pore-forming lantibiotic epidermin is mediat ed by an ABC transporter composed of the EpiF, EpiE, and EpiG proteins . We developed a sensitive assay based on HPLC analysis to investigate the capacity of the EpiFEG transporter to release epidermin and analo gues from the cell surface to the external fluid. Our results indicate that the EpiFEG transporter works by expelling the lantibiotic from t he cytoplasmic membrane into the surrounding medium. Analysis of trans porter efficacy using nisin and gallidermin derivatives as substrates revealed a high substrate specificity. Furthermore, we showed that the activity of the gallidermin derivative L6G is enhanced by the presenc e of EpiE. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.