Dissociation of RecA filaments from duplex DNA by the RuvA and RuvB DNA repair proteins.
The RuvA and RuvB proteins of Escherichia coli act late in recombination and DNA repair to catalyze the branch migration of Holliday junctions made by RecA. In this paper, we show that addition of RuvAB to supercoiled DNA that is bound by RecA leads to the rapid dissociation of the RecA nucleoprotein filament, as determined by a topological assay that measures DNA underwinding and a restriction endonuclease protection assay. Disruption of the RecA filament requires RuvA, RuvB, and hydrolysis of ATP. These findings suggest several important roles for the RuvAB helicase during genetic recombination and DNA repair: (i) displacement of RecA filaments from double-stranded DNA, (ii) interruption of RecA-mediated strand exchange, (iii) RuvAB-catalyzed branch migration, and (iv) recycling of RecA protein.
Adams
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DE
Imperial Cancer Research Fund, South Mimms, Herts, United Kingdom.
Tsaneva
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West
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SC
D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007700:Kinetics; D008961:Models, Structural; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011938:Rec A Recombinases / Q000737:chemistry / Q000378:metabolism*; D015183:Restriction Mapping; D014908:Triticum / Q000201:enzymology
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C061260:RuvB protein, Bacteria; D011938:Rec A Recombinases; C071059:Holliday junction DNA helicase, E coli; D004265:DNA Helicases; D004264:DNA Topoisomerases, Type I