The SOS response controls integron recombination

Science. 2009 May 22;324(5930):1034. doi: 10.1126/science.1172914.


Integrons are found in the genome of hundreds of environmental bacteria but are mainly known for their role in the capture and spread of antibiotic resistance determinants among Gram-negative pathogens. We report a direct link between this system and the ubiquitous SOS response. We found that LexA controlled expression of most integron integrases and consequently regulated cassette recombination. This regulatory coupling enhanced the potential for cassette swapping and capture in cells under stress, while minimizing cassette rearrangements or loss in constant environments. This finding exposes integrons as integrated adaptive systems and has implications for antibiotic treatment policies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Base Sequence
  • Binding Sites
  • Drug Resistance, Bacterial / genetics
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Bacterial
  • Integrases / genetics
  • Integrons / genetics*
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Recombination, Genetic*
  • SOS Response, Genetics*
  • Serine Endopeptidases / metabolism
  • Vibrio cholerae / genetics*
  • Vibrio cholerae / metabolism


  • Bacterial Proteins
  • LexA protein, Bacteria
  • Integrases
  • Serine Endopeptidases

Associated data

  • GENBANK/AB070224
  • GENBANK/AF034958
  • GENBANK/AF055586
  • GENBANK/AJ001816
  • GENBANK/AJ277063
  • GENBANK/AY014398
  • GENBANK/AY014399
  • GENBANK/AY181034