IS 200: an old and still bacterial transposon

• Carmen R. Beuzón ^[1] ; Daniela Chessa ^[1] ; Josep Casadesús ^[1]
  1. [1] Universidad de Sevilla

     Universidad de Sevilla

     Sevilla, España

     
• Localización: International microbiology: official journal of the Spanish Society for Microbiology, ISSN 1139-6709, Vol. 7, Nº. 1, 2004, págs. 3-12
• Idioma: inglés
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• Resumen

  • IS 200 is a mobile element found in a variety of eubacterial genera, such as Salmonella, Escherichia, Shigella, Vibrio, Enterococcus, Clostridium, Helicobacter, and Actinobacillus. In addition, IS200-like elements are found in archaea. IS 200 elements are very small (707–711 bp) and contain a single gene. Cladograms constructed with IS200 DNA sequences suggest that IS 200 has not spread among eubacteria by horizontal transfer; thus it may be an ancestral component of the bacterial genome. Self-restraint may have favored this evolutionary endurance; in fact, unlike typical mobile elements, IS 200 transposes rarely. Tight repression of transposase synthesis is achieved by a combination of mechanisms: inefficient transcription, protection from impinging transcription by a transcriptional terminator, and repression of translation by a stem-loop mRNA structure. A consequence of IS 200 self-restraint is that the number and distribution of IS 200