Figure 8.

Homologous Recombination (HR) Repair of DSBs. (A) HR begins with the 5′-3′ extensive resection of break ends by MRN complex to (B) generate 3′ ssDNA overhangs that are coated with RPA. Once the DNA ends are captured, ATM and ATR kinases trigger downstream signaling to facilitate DNA repair through HR. (C) Rad51 is then loaded onto the ssDNA in a BRCA-dependent manner, replacing RPA and forming a nucleoprotein filament, which (D) initiates the homology search for complementary sequences. (E) This prompts DNA strand invasion, where the 3′ end of the invading strand primes DNA synthesis off the sister chromatid. (F) After DNA synthesis extends past the DSB, it is precisely repaired.