title: Novel recA-Independent Horizontal Gene Transfer in Escherichia coli K-12.
abstract: In bacteria, mechanisms that incorporate DNA into a genome without strand-transfer proteins such as RecA play a major role in generating novelty by horizontal gene transfer. We describe a new illegitimate recombination event in Escherichia coli K-12: RecA-independent homologous replacements, with very large (megabase-length) donor patches replacing recipient DNA. A previously uncharacterized gene (yjiP) increases the frequency of RecA-independent replacement recombination. To show this, we used conjugal DNA transfer, combining a classical conjugation donor, HfrH, with modern genome engineering methods and whole genome sequencing analysis to enable interrogation of genetic dependence of integration mechanisms and characterization of recombination products. As in classical experiments, genomic DNA transfer begins at a unique position in the donor, entering the recipient via conjugation; antibiotic resistance markers are then used to select recombinant progeny. Different configurations of this system were used to compare known mechanisms for stable DNA incorporation, including homologous recombination, F'-plasmid formation, and genome duplication. A genome island of interest known as the immigration control region was specifically replaced in a minority of recombinants, at a frequency of 3 X 10(-12) CFU/recipient per hour.
authors.affiliation: New England Biolabs, Ipswich, Massachusetts, 01938, United States of America.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Kingston
authors.affiliation: New England Biolabs, Ipswich, Massachusetts, 01938, United States of America.
authors.forename: Chloé
authors.initials: C
authors.lastname: Roussel-Rossin
authors.affiliation: New England Biolabs, Ipswich, Massachusetts, 01938, United States of America.
authors.forename: Claire
authors.initials: C
authors.lastname: Dupont
authors.affiliation: New England Biolabs, Ipswich, Massachusetts, 01938, United States of America.
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Raleigh
mesh_terms: D002876:Chromosomes, Bacterial / Q000235:genetics; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D048168:Escherichia coli K12 / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial / Q000235:genetics; D044404:Genomic Islands / Q000235:genetics; D059765:Homologous Recombination; D008957:Models, Genetic; D011938:Rec A Recombinases / Q000235:genetics* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D011938:Rec A Recombinases