IS 200: an old and still bacterial transposon Authors Carmen R. Beuzón Department of Genetics, School of Biology, University of Seville, Spain Daniela Chessa Department of Genetics, School of Biology, University of Seville, Spain Josep Casadesús Department of Genetics, School of Biology, University of Seville, Spain Keywords: transposition, DNA rearrangements, genome evolution, parasite attenuation, IS200 fingerprints Abstract 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 elements remain fairly constant in natural populations of bacteria. This stability makes IS 200 suitable molecular marker for epidemiological and ecological studies, especially when the number of IS 200 copies is high. In Salmonella enterica, IS 200 fingerprinting is extensively used for strain discrimination. [Int Microbiol 2004; 7(1):3–12] Downloads PDF Published 2010-03-03 Issue Vol. 7 No. 1 (2004) Section Research Reviews License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
