Control of crossing over.
The Holliday junction is a central intermediate in homologous recombination. It consists of a four-way structure that can be resolved by cleavage to give either the crossover or noncrossover products observed. We show here that the formation of these products is controlled by the E. coli resolvasome (RuvABC) in such way that double-strand break repair (DSBR) leads to crossing over and single-strand gap repair (SSGR) does not lead to crossing over. We argue that the positioning of the RuvABC complex and its consequent direction of junction-cleavage is not random. In fact, the action of the RuvABC complex avoids crossing over in the most commonly predicted situations where Holliday junctions are encountered in DNA replication and repair. Our observations suggest that the positioning of the resolvasome may provide a general biochemical mechanism by which cells can control crossing over in recombination.
Cromie
G A
GA
Institute of Cell and Molecular Biology, University of Edinburgh, United Kingdom.
Leach
D R
DR
D001426:Bacterial Proteins / Q000378:metabolism; D003434:Crossing Over, Genetic; D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000528:radiation effects; D029968:Escherichia coli Proteins; D005838:Genotype; D045565:Holliday Junction Resolvases; D008957:Models, Genetic; D016296:Mutagenesis; D014161:Transduction, Genetic; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C061260:RuvB protein, Bacteria; C069806:ruvC protein, E coli; D004706:Endodeoxyribonucleases; D045565:Holliday Junction Resolvases; C071059:Holliday junction DNA helicase, E coli; D004265:DNA Helicases