Integrons: agents of bacterial evolution.
Integrons are assembly platforms - DNA elements that acquire open reading frames embedded in exogenous gene cassettes and convert them to functional genes by ensuring their correct expression. They were first identified by virtue of their important role in the spread of antibiotic-resistance genes. More recently, our understanding of their importance in bacterial genome evolution has broadened with the discovery of larger integron structures, termed superintegrons. These DNA elements contain hundreds of accessory genes and constitute a significant fraction of the genomes of many bacterial species. Here, the basic biology of integrons and superintegrons, their evolutionary history and the evidence for the existence of a novel recombination pathway is reviewed.
Mazel
Didier
D
Unité Plasticité du Génome Bactérien- CNRS URA 2171, Department Génomes et Génétique, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France. mazel@pasteur.fr
D001287:Attachment Sites, Microbiological / Q000502:physiology; D001419:Bacteria / Q000235:genetics*; D001483:Base Sequence; D020562:Betaproteobacteria / Q000235:genetics; D020564:Deltaproteobacteria / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D020563:Gammaproteobacteria / Q000235:genetics; D016680:Genome, Bacterial; D019426:Integrases; D032023:Integrons / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic
D019426:Integrases