title: Mu insertions are repaired by the double-strand break repair pathway of Escherichia coli.
abstract: Mu is both a transposable element and a temperate bacteriophage. During lytic growth, it amplifies its genome by replicative transposition. During infection, it integrates into the Escherichia coli chromosome through a mechanism not requiring extensive DNA replication. In the latter pathway, the transposition intermediate is repaired by transposase-mediated resecting of the 5' flaps attached to the ends of the incoming Mu genome, followed by filling the remaining 5 bp gaps at each end of the Mu insertion. It is widely assumed that the gaps are repaired by a gap-filling host polymerase. Using the E. coli Keio Collection to screen for mutants defective in recovery of stable Mu insertions, we show in this study that the gaps are repaired by the machinery responsible for the repair of double-strand breaks in E. coli-the replication restart proteins PriA-DnaT and homologous recombination proteins RecABC. We discuss alternate models for recombinational repair of the Mu gaps.
authors.affiliation: Institute of Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.
authors.forename: Sooin
authors.initials: S
authors.lastname: Jang
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Sandler
authors.forename: Rasika M
authors.initials: RM
authors.lastname: Harshey
mesh_terms: D010583:Bacteriophage mu / Q000235:genetics / Q000254:growth & development; D053903:DNA Breaks, Double-Stranded; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D016678:Genome; D059765:Homologous Recombination / Q000235:genetics*; D016254:Mutagenesis, Insertional; D009154:Mutation; D019895:Transposases / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; C104198:DnaT protein, E coli; D029968:Escherichia coli Proteins; D019895:Transposases; C506743:priA protein, E coli; D004265:DNA Helicases