DNA sequencing and homologous expression of a small peptide conferring immunity to gassericin a, a circular bacteriocin a produced by lactobacillus gasseri LA39

Yasushi Kawai, Joni Kusnadi, Rober Kemperman, Jan Kok, Yoshiyuki Ito, Mikiko Endo, Kensuke Arakawa, Hideaki Uchida, Junko Nishimura, Haruki Kitazawa, Tadao Saito

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18 Citations (Scopus)


Gassericin A, produced by Lactobacillus gasseri LA39, is a hydrophobic circular bacteriocin. The DNA region surrounding the gassericin A structural gene, gaaA, was sequenced, and seven open reading frames (ORFs) of 3.5 kbp (gaaBCADITE) were found with possible functions in gassericin A production, secretion, and immunity. The deduced products of the five consecutive ORFs gaaADITE have homology to those of genes involved in butyrivibriocin AR10 production, although the genetic arrangements are different in the two circular bacteriocin genes. Gaal is a small, positively charged hydrophobic peptide of 53 amino acids containing a putative transmembrane segment. Heterologous expression and homologous expression of Gaal in Lactococcus lactis subsp. cremoris MG1363 and L. gasseri JCM1131T, respectively, were studied. Gaal-expressing strains exhibited at least sevenfold-higher resistance to gassericin A than corresponding control strains, indicating that goal encodes an immunity peptide for gassericin A. Comparison of Gaal to peptides with similar characteristics found in the circular bacteriocin gene loci is discussed.

Original languageEnglish
Pages (from-to)1324-1330
Number of pages7
JournalApplied and Environmental Microbiology
Issue number5
Publication statusPublished - Mar 2009
Externally publishedYes


ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Food Science
  • Biotechnology
  • Ecology

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