Affiliation:
1. Department of Food Science, Southeast Dairy Foods Research Center, North Carolina State University, Raleigh 27695-7624.
Abstract
Lactacin F is a nonlantibiotic, heat-stable, peptide bacteriocin produced by Lactobacillus johnsonii VPI11088. Molecular analysis of the lactacin F DNA region characterized a small operon that codes for three open reading frames, designated lafA, lafX, and ORFZ. The peptide encoded by lafA, the lactacin F structural gene, was compared with various peptide bacteriocins from lactic acid bacteria, and similarities were identified in the amino and carboxy termini of the propeptides. Site-directed mutagenesis of the LafA precursor at the two glycine residues in positions -1 and -2 defined an essential motif for processing of mature lactacin F. The involvement of the peptides encoded by lafX and ORFZ in bacteriocin expression was investigated by subcloning various fragments from the lactacin F region into the shuttle vector pGKV210. In addition to lafA, expression of lafX is essential to lactacin F activity. The lactacin F operon resembles the genetic organization of lactococcin M. Although no function has been assigned to ORFZ by genetic analysis, both peptide Z and the lactococcin M immunity protein are predicted to be integral membrane proteins with four putative transmembrane segments. Lactacin F activity, defined by bactericidal action on Lactobacillus delbrueckii, is dependent on the expression of two genes, lafA and lafX.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference51 articles.
1. Expansion of the bactericidal activity of lactacin F by complementation with a second peptide encoded within the laf operon;Allison G.;FEMS Microbiol. Rev.,1993
2. Detection and activity of lactacin B, a bacteriocin produced by Lactobacillus acidophilus;Barefoot S. F.;Appl. Environ. Microbiol.,1983
3. A membrane-filter technique for the detection of complementary DNA;Denhardt D. T.;Biochem. Biophys. Res. Commun.,1966
4. High efficiency transformation of Eschenchia coli by high voltage electroporation;Dower W. J.;Nucleic Acids Res.,1988
5. Biosynthesis of the lantibiotic nisin: genomic organization and membrane localization of the NisB protein;Engelke G.;Appl. Environ. Microbiol.,1992
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