Spatial controls of homology search

Homologous recombination is a conserved DNA double-strand break repair pathway that uses an intact dsDNA molecule as a template. A filament of the RecA/Rad51 protein family catalyzes the search for this homologous template, in a process that minimally requires the collision of these two partners in the nuclear space. Orthogonal methodological developments recently revealed that this search for homology is a choreographed process under control by both 3D chromatin organizers of the structural maintenance of chromosomes family and the structure and dynamics of the RecA/Rad51 filament. Here, we review these advances that establish a novel framework for homology search, highlight the commonalities and distinctions between search facilitation strategies in eukaryotes and bacteria, and discuss outstanding open questions.