Characterization of the genetic locus responsible for the production of ABP-118, a novel bacteriocin produced by the probiotic bacterium Lactobacillus salivarius subsp. salivarius UCC118.
ABP-118, a small heat-stable bacteriocin produced by Lactobacillus salivarius subsp. salivarius UCC118, a strain isolated from the ileal-caecal region of the human gastrointestinal tract, was purified to homogeneity. Using reverse genetics, a DNA fragment specifying part of ABP-118 was identified on a 10769 bp chromosomal region. Analysis of this region revealed that ABP-118 was a Class IIb two-peptide bacteriocin composed of Abp118alpha, which exhibited the antimicrobial activity, and Abp118beta, which enhanced the antimicrobial activity. The gene conferring strain UCC118 immunity to the action of ABP-118, abpIM, was identified downstream of the abp118beta gene. Located further downstream of abp118beta, several ORFs were identified whose deduced proteins resembled those of proteins involved in bacteriocin regulation and secretion. Heterologous expression of ABP-118 was achieved in Lactobacillus plantarum, Lactococcus lactis and Bacillus cereus. In addition, the abp118 locus encoded an inducing peptide, AbpIP, which was shown to play a role in the regulation of ABP-118 production. This novel bacteriocin is, to the authors' knowledge, the first to be isolated from a known human probiotic bacterium and to be characterized at the genetic level.
Flynn
Sarah
S
National Food Biotechnology Centre1, Department of Microbiology2, Department of Medicine4, University College Cork, Cork, Ireland.
van Sinderen
Douwe
D
National Food Biotechnology Centre1, Department of Microbiology2, Department of Medicine4, University College Cork, Cork, Ireland.
Thornton
Gerardine M
GM
National Food Biotechnology Centre1, Department of Microbiology2, Department of Medicine4, University College Cork, Cork, Ireland.
Holo
Helge
H
Laboratory of Microbial Gene Technology, Agricultural University of Norway, N-1432 Ås, Norway3.
Nes
Ingolf F
IF
Laboratory of Microbial Gene Technology, Agricultural University of Norway, N-1432 Ås, Norway3.
Collins
J Kevin
JK
National Food Biotechnology Centre1, Department of Microbiology2, Department of Medicine4, University College Cork, Cork, Ireland.
D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics*; D002874:Chromosome Mapping; D015964:Gene Expression Regulation, Bacterial; D007778:Lactobacillus / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D010957:Plasmids; D021382:Protein Sorting Signals
C459788:ABP-118 protein, Lactobacillus salivarius; D001430:Bacteriocins; D021382:Protein Sorting Signals