Characterization of leucocin B-Ta11a: a bacteriocin from Leuconostoc carnosum Ta11a isolated from meat.
Leuconostoc (Lc.) carnosum Ta11a, isolated from vacuum-packaged processed meats, produced a bacteriocin designated leucocin B-Ta11a. The crude bacteriocin was heat stable and sensitive to proteolytic enzymes, but not to catalase, lysozyme, or chloroform. It was active against Listeria monocytogenes and several lactic acid bacteria. Leucocin B-Ta11a was optimally produced at 25 degrees C in MRS broth at an initial pH of 6.0 or 6.5. An 8.9-MDa plasmid in Leuconostoc carnosum Ta11a hybridized to a 36-mer oligonucleotide probe (JF-1) that was homologous to leucocin A-UAL187. A 4.9-kb Sau3A fragment from a partial digest of the 8.9-MDa plasmid was cloned into pUC118. The 8.1-kb recombinant plasmid (pJF8.1) was used for sequencing and revealed the presence of two open reading frames (ORFs). ORF1 codes for a protein of 61 amino acids comprising a 37-amino-acid bacteriocin that was determined to be the leucocin B-Ta11a structural gene by virtue of its homology to leucocin A-UAL 187 (Hastings et al. 1991. J. Bacteriol 173:7491-7500). The 24-amino-acid N-terminal extension, however, differs from that of leucocin A-UAL187 by seven residues. The predicted protein of the ORF2 has 113 amino acids and is identical with the amino acid sequence of the cognate ORF of the leucocin A-UAL 187 operon.
Felix
J V
JV
Department of Microbiology, University of the Western Cape, Bellville, South Africa.
Papathanasopoulos
M A
MA
Smith
A A
AA
von Holy
A
A
Hastings
J W
JW
D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D010450:Endopeptidases / Q000494:pharmacology; D005506:Food Contamination; D005798:Genes, Bacterial; D007934:Leuconostoc / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D008460:Meat / Q000382:microbiology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D001430:Bacteriocins; C090316:leucocin B-Ta11a; C079275:mesentericin Y105 protein, Leuconostoc mesenteroides; C071726:leucocin A-UAL 187; D010450:Endopeptidases