Posttranslationally modified bacteriocins - The lantibiotics

Lantibiotics are a subgroup of bacteriocins that are characterized by the p resence of the unusual thioether amino acids lanthionine and 3-methyllanthi onine generated through posttranslational modification. The biosynthesis of lantibiotics follows a defined pathway comprising modifications of the pre peptide, proteolytic activation,and export. The genes encoding the biosynth esis apparatus and the lantibiotic prepeptide ar organized in clusters, whi ch also include information for proteins involved in regulation and produce r self-protection. The elongated cationic lantibiotics primarily act throug h the formation of pores and recent progress with nisin and epidermin has s hown that specific docking molecules such as lipid II play an essential rol e in this mechanism. Mersacidin and actagardine inhibit cell wall biosynthe sis by complexing the precursor lipid II, whereas the cinnamycin-like pepti des bind to phosphoethanolamine thus inhibiting phospholipase A2. (C) 2000 John Wiley & Sons, Inc.