Characterization and Distribution of Two Insertion Sequences, IS1191 and iso-IS981, in Streptococcus Thermophilus: Does Intergeneric Transfer of Insertion Sequences Occur in Lactic Acid Bacteria Co-Cultures?

Mol Microbiol. 1995 Apr;16(1):69-78. doi: 10.1111/j.1365-2958.1995.tb02392.x.


A chromosomal repeated sequence from Streptococcus thermophilus was identified as a new insertion sequence (IS), IS1191. This is the first IS element characterized in this species. This 1313 bp element has 28 bp imperfect terminal inverted repeats and is flanked by short direct repeats of 8 bp. The single large open reading frame of IS1191 encodes a 391-amino-acid protein which displays homologies with transposases encodes by IS1201 from Lactobacillus helveticus (44.5% amino-acid sequence identity) and by the other ISs of the IS256 family. One of the copies of IS1191 is inserted into a truncated iso-IS981 element. The nucleotide sequences of two truncated iso-IS981s from S. thermophilus and the sequence of IS981 element from Lactococcus lactis share more than 99% identity. The distribution of these insertion sequences in L. lactis and S. thermophilus strains suggests that intergeneric transfers occur during cocultures used in the manufacture of cheese.

MeSH terms

  • Bacteria / genetics
  • Base Sequence
  • Blotting, Southern
  • Cloning, Molecular
  • DNA Transposable Elements / genetics*
  • Gene Transfer Techniques
  • Genome, Bacterial*
  • Lactobacillus / genetics
  • Lactococcus lactis / genetics*
  • Molecular Sequence Data
  • Nucleotidyltransferases / genetics
  • Phylogeny
  • Repetitive Sequences, Nucleic Acid
  • Restriction Mapping
  • Streptococcaceae / genetics
  • Streptococcus / genetics*
  • Transposases


  • DNA Transposable Elements
  • Nucleotidyltransferases
  • Transposases

Associated data

  • GENBANK/L32789
  • GENBANK/L32790
  • GENBANK/X71808
  • GENBANK/Z46839
  • GENBANK/Z46840
  • GENBANK/Z46841
  • GENBANK/Z46842