Cloning of the gene encoding a novel lantibiotic, nukacin ISK-1, of Staphylococcus warneri

Staphylococcus warneri ISK-1, we had reported as Pediococcus sp. ISK-1 prev iously, produces a novel bacteriocin, nukacin ISK-1, Edman degradation of t he chemically reduced nukacin ISK-1 revealed a sequence of 27 amino acids, 7 of which were unidentified. Using single-specific-primer-PCR (SSP-PCR) pr oduct as a probe, a 3.6-kb HindIII fragment containing nukacin ISK-1 struct ural gene (nukA) was cloned and sequenced. The deduced amino acid sequence of nukacin ISK-1 revealed that it was comprised of 57-amino acids, includin g a 30-amino acid leader region. The propeptide sequence showed significant similarity to those of lacticin-481 type lantibiotics. It was expected tha t an active 27-residue nukacin ISK-1 contained two lanthionines, one 3-meth yllanthionine, and one dehydrobutyrine. In the region upstream of nukA, a p art of long open reading frame (ORF), designated as nukM, encoding a putati ve modification enzyme involved in the lantibiotic biosynthesis, was orient ed in the opposite direction. In the region of dowmstream of nukA, ORF1 was found, in which the sequence of the putative translational product was sim ilar to those of response regulatory proteins such as LytT of Bacillus subt ilis and VirR of Clostridium perfringens.