Characterization of RAD51-independent break-induced replication that acts preferentially with short homologous sequences.
Repair of double-strand breaks by gene conversions between homologous sequences located on different Saccharomyces cerevisiae chromosomes or plasmids requires RAD51. When repair occurs between inverted repeats of the same plasmid, both RAD51-dependent and RAD51-independent repairs are found. Completion of RAD51-independent plasmid repair events requires RAD52, RAD50, RAD59, TID1 (RDH54), and SRS2 and appears to involve break-induced replication coupled to single-strand annealing. Surprisingly, RAD51-independent recombination requires much less homology (30 bp) for strand invasion than does RAD51-dependent repair (approximately 100 bp); in fact, the presence of Rad51p impairs recombination with short homology. The differences between the RAD51- and RAD50/RAD59-dependent pathways account for the distinct ways that two different recombination processes maintain yeast telomeres in the absence of telomerase.
Rosenstiel Center and Department of Biology, Brandeis University, Waltham, Massachussetts 02454-9110, USA.
Grzegorz
G
Ira
James E
JE
Haber
D002875:Chromosomes / Q000648:ultrastructure; D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D010957:Plasmids / Q000378:metabolism; D051135:Rad51 Recombinase; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D019098:Telomerase / Q000378:metabolism
D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D019098:Telomerase