title: Four genes essential for recombination define GInts, a new type of mobile genomic island widespread in bacteria.
abstract: Integrases are a family of tyrosine recombinases that are highly abundant in bacterial genomes, actively disseminating adaptive characters such as pathogenicity determinants and antibiotics resistance. Using comparative genomics and functional assays, we identified a novel type of mobile genetic element, the GInt, in many diverse bacterial groups but not in archaea. Integrated as genomic islands, GInts show a tripartite structure consisting of the ginABCD operon, a cargo DNA region from 2.5 to at least 70 kb, and a short AT-rich 3' end. The gin operon is characteristic of GInts and codes for three putative integrases and a small putative helix-loop-helix protein, all of which are essential for integration and excision of the element. Genes in the cargo DNA are acquired mostly from phylogenetically related bacteria and often code for traits that might increase fitness, such as resistance to antimicrobials or virulence. GInts also tend to capture clusters of genes involved in complex processes, such as the biosynthesis of phaseolotoxin by Pseudomonas syringae. GInts integrate site-specifically, generating two flanking direct imperfect repeats, and excise forming circular molecules. The excision process generates sequence variants at the element attachment site, which can increase frequency of integration and drive target specificity.
authors.affiliation: Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, 31006 Pamplona, Spain.
authors.forename: Leire
authors.initials: L
authors.lastname: Bardaji
authors.affiliation: Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, 31006 Pamplona, Spain.
authors.forename: Myriam
authors.initials: M
authors.lastname: Echeverría
authors.affiliation: Centro de Biotecnología y Genómica de Plantas, E.T.S. Ingenieros Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, E-28223 Pozuelo de Alarcón, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-Palenzuela
authors.affiliation: Centro de Biotecnología y Genómica de Plantas, E.T.S. Ingenieros Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, E-28223 Pozuelo de Alarcón, Madrid, Spain.|Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Área de Genética, Facultad de Ciencias, Campus Teatinos s/n, 29010 Málaga, Spain.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Martínez-García
authors.affiliation: Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, 31006 Pamplona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Murillo
mesh_terms: D001419:Bacteria / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004270:DNA, Circular / Q000235:genetics; D005798:Genes, Bacterial; D020043:Genes, Essential; D044404:Genomic Islands / Q000235:genetics*; D009876:Operon / Q000235:genetics; D011995:Recombination, Genetic; D013045:Species Specificity
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular