Abstract
The repair of chromosomal double‐strand breaks (DSBs) by homologous recombination is essential to maintain genome integrity. The key step in DSB repair is the RecA/Rad51‐mediated process to match sequences at the broken end to homologous donor sequences that can be used as a template to repair the lesion. Here, in reviewing research about DSB repair, I consider the many factors that appear to play important roles in the successful search for homology by several homologous recombination mechanisms. See also the video here: https://youtu.be/vm7-X5uIzS8.
The key step in repairing a double‐strand DNA break in a chromosome is finding an homologous segment that can be used as a template to repair the break. The search for homology is carried out by a Rad51 nucleoprotein filament (spheres) that forms on single‐stranded DNA that is revealed by resection of the broken ends. The pairing with a sequence homologous to the single‐strand (black) is governed by many factors, reviewed in this article. Illustrated is the importance of proximity of such sequences in the nucleus when there is a choice of possible donor sequences.