Studies in the model eukaryote Saccharomyces cerevisiae have revealed that homologous recombination (HR) provides a major mechanism for eliminating DNA double-stranded breaks (DSBs) induced by ionizing radiation or are associated with injured DNA replication forks. During the repair process, the ends of the DNA breaks are resected nucleolytically to yield 3' ssDNA tails, which are bound by HR factors. The nucleoprotein complex thus formed then conducts a search to locate an undamaged DNA homolog, and catalyzes the formation of a DNA joint, called D-loop, with the homolog.
