title: Induction of bacteriocin production in Lactobacillus sake by a secreted peptide.
abstract: Lactobacillus sake LTH673 is known to produce a bacteriocin called sakacin P. Production of and immunity to sakacin P were found to depend on the presence of a protease-sensitive component that is produced by L. sake LTH673 itself. This component (called inducing factor [IF]) was purified from culture supernatants and shown to be a basic, nonbacteriocin peptide consisting of 19 amino acids, which in principle is capable of forming a highly amphiphilic helical structure. Circular dichroism studies showed that IF indeed could adopt a helical structure, but only in membrane-mimicking environments. Both purified IF and chemically synthesized IF induced expression of the structural gene for sakacin P and concomitant secretion of the gene product. In addition, IF induced its own production and immunity to sakacin P and related bacteriocins. These results indicate that bacteriocin production by L. sake LTH673 is controlled by an autoinduction pathway in which IF may function as a cell density signal.
authors.affiliation: Laboratory of Microbial Gene Technology, Department of Biotechnological Sciences, Agricultural University of Norway, As.
authors.forename: V G
authors.initials: VG
authors.lastname: Eijsink
authors.forename: M B
authors.initials: MB
authors.lastname: Brurberg
authors.forename: P H
authors.initials: PH
authors.lastname: Middelhoven
authors.forename: I F
authors.initials: IF
authors.lastname: Nes
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001430:Bacteriocins / Q000096:biosynthesis*; D001483:Base Sequence; D002942:Circular Dichroism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D047908:Intracellular Signaling Peptides and Proteins; D007778:Lactobacillus / Q000235:genetics*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D047908:Intracellular Signaling Peptides and Proteins; D010455:Peptides; C098845:inducing factor, Lactobacillus; C087217:sakacin P protein, Lactobacillus