Identification and characterization of the lantibiotic nisin Z, a natural nisin variant

has been cloned and its nucleotide sequence was found to be identical to that of the precursor nisin gene apart from a single mutation resulting in the substitution His27Asn in the mature polypeptide. NMR studies of the natural nisin variant, which has been designated nisin Z, confirmed the His27Asn substitution and indicated that it has a similar structure to nisin. Lantibiotics are ribosomally synthesized antimicrobial polypeptides containing the unusual amino acids lanthionine and fl-methyllanthionine [I]. Genetic analysis has shown that the lantibiotics are produced as precursor molecules consisting of an uncommon leader region and a structural region that is post-translationally processed [1