- Integron
An integron is a
gene capture system found in plasmids, chromosomes and transposons. Pieces ofDNA calledgene cassette s can be incorporated, expressed, and disseminated.An integron with a large number of cassettes may be called a super-integron, as in
Vibrio cholerae chromosome 2. A cassette may encode genes forantibiotic resistance , although most genes in integrons are uncharacterized. An integron contains anintegrase (int1) related to those of aphage , followed by an "attI" site for integration of cassettes and recognition of the integrase [ Hall,R.M., Collis, C.M. (1995)Mobile gene cassettes and integrons:capture and spread of genes by site-specific recombination"Mol Microbiol" Feb;15(4):593-600.] , and apromoter to drive expression. An integron may appear in aplasmid or on the chromosome. An "attC" sequence (also called 59-be) is a repeat that flanks cassettes and enables cassettes to be integrated at the "attI" site, excised and undergohorizontal gene transfer .A functional integron "platform" requires [ Mobile Gene Cassettes and Integrons, Kovalevskaya, "Molecular Biology", Vol 36 No 2] :::*an
integrase : "intI", a tyrosine recombinase responsible for incorporation into the genome::*a proximalrecombination site: "attI", which acts as the locus for reincorporation to the genome. It combines with a "attC" site at the insertion site."Further reading
* [http://jb.asm.org/cgi/content/abstract/184/11/3017 Journal of Bacteriology, June 2002, p. 3017-3026, Vol. 184, No. 11] article "Characterization of the Class 3 Integron and the Site-Specific Recombination System It Determines"
* [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9835490&dopt=Abstract NCBI Antimicrob Agents Chemother. 1998 Dec;42(12):3053-8.] article "Class 1 integron-borne multiple-antibiotic resistance carried by IncFI and IncL/M plasmids in Salmonella enterica serotype typhimurium
* [http://dx.doi.org/10.1038/nrmicro1462 Nature Reviews Microbiology 4, 608-620.] Mazel, D. Integrons: agents of bacterial evolutionources
* [http://www.medterms.com/script/main/art.asp?articlekey=32273 Medical terms]
References
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