RecA finds homologous DNA by reduced dimensionality search

Homologous recombination is essential for the accurate repair of double-stranded DNA breaks (DSBs). Initially, RecBCD complex resects ends DSB into 3′ single-stranded on which a RecA filament assembles. Next, locates homologous template sister chromosome. Here we directly visualize DSBs in single cells, using high-throughput microfluidics and fluorescence microscopy. We find that, Escherichia coli, between segregated loci completed 15 ± 5 min (mean s.d.) with minimal fitness loss.