title: Loss of lambda prophage recombinogenicity in UV-irradiated Escherichia coli: the role of host genes ruvA, ruvB, ruvC, and recG.
abstract: Earlier studies have revealed a radiation-induced process leading to the loss of lambda prophage recombinogenicity. The process takes place in UV-irradiated Escherichia coli cells, and renders the prophage incapable of site-specific recombination with the host chromosome, and of general recombination with an infecting homologous phage. It was found that the inhibition of prophage recombinogenicity depends on functional RecBCD enzyme of E. coli. In this work, the role of ruvABC and recG genes in the inhibitory process was assessed. The products of these genes are known to act at the last step of homologous recombination and recombinational DNA repair by catalyzing the resolution of recombination intermediates (the Holliday junctions). Irradiated prophage retained its ability to recombine in ruvA, ruvB, ruvC, and recG mutants. These results suggest that in addition to RecBCD enzyme, RuvABC and RecG proteins are also involved in the inhibition of prophage recombinogenicity. We infer that RuvABC and RecG act in this process before RecBCD, probably by processing the Holliday junctions formed upon replication arrest, and thereby providing double-stranded DNA breaks as substrate for RecBCD-mediated recombinational repair of UV-damaged bacterial chromosome.
authors.affiliation: Department of Molecular Genetics, Ruder Bosković Institute, Zagreb, Croatia. kvlahovi@rudjer.irb.hr
authors.forename: K
authors.initials: K
authors.lastname: Zahradka
authors.forename: D
authors.initials: D
authors.lastname: Zahradka
authors.forename: M
authors.initials: M
authors.lastname: Petranović
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D010582:Bacteriophage lambda / Q000235:genetics / Q000502:physiology*; D004265:DNA Helicases; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000528:radiation effects; D004706:Endodeoxyribonucleases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects / Q000821:virology*; D029968:Escherichia coli Proteins; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000528:radiation effects; D009154:Mutation; D011995:Recombination, Genetic; D014466:Ultraviolet Rays; D014775:Virus Activation
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C061260:RuvB protein, Bacteria; C069806:ruvC protein, E coli; C071446:RecG protein, E coli; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V; C071059:Holliday junction DNA helicase, E coli; D004265:DNA Helicases