COMPLETE NUCLEOTIDE-SEQUENCE OF PSMB-74, A PLASMID ENCODING THE PRODUCTION OF PEDIOCIN ACH IN PEDIOCOCCUS-ACIDILACTICI

Several Pediococcus acidilactici strains produce a plasmid-encoded bac teriocin, pediocin AcH. Previous studies have shown that this plasmid, designated as pSMB 74, encodes genes associated with the production o f prepediocin, its post-translation processing to pediocin AcH, transm embrane translocation of these molecules, and immunity of producer cel ls against pediocin AcH. We report here the complete nucleotide sequen ce of pSMB 74. The plasmid has a total of 8877 bp. Four genes have bee n located on pSMB 74. The genes are arranged in a gene cluster of 3500 bp and share a common promoter and rho-independent stem-loop terminat or. The four genes, each with independent ribosome binding sites (rbs) , initiation and termination codons and spacer sequences in between, w ere designated as pap A, pap B, pap C and pap D and encode respectivel y for proteins of 62, 112, 174 and 724 amino acids. The results of thi s study can be useful either to introduce a suitable marker at a uniqu e restriction site in pSMB 74 and use it as a vector or to clone the p ap gene cluster in a suitable plasmid and transform desirable strains for pediocin AcH production. The gene sequence has been submitted to G ene Bank (Acc. No. U02482).