Homologous Recombination by the RecBCD and RecF Pathways

In all cells, genetic recombination is used to repair DNA breaks and, as a result, genetic information is exchanged between homologous DNA molecules. Discontinuities in DNA strands, specifically double-strand DNA breaks and single-strand DNA gaps, attract the enzymes responsible for the initiation of homologous recombination. In wild-type Escherichia coli, two distinct pathways are responsible for the repair of DNA by recombination: the RecBCDand the RecF-pathways. The RecBCD-pathway is specific to recombination initiated at double-strand DNA breaks, whereas the RecF-pathway is primarily responsible for recombination initiated at single-strand DNA gaps, although it can also act at double-strand breaks. This review summarizes the biochemical mechanisms of homologous recombination in E. coli.