On the influence of protein-DNA register during homologous recombination.

Homologous recombination enables the exchange of genetic information between related DNA molecules and is a driving force in evolution. Using single-molecule optical microscopy we have recently shown that members of the Rad51/RecA family of recombinases stabilize paired homologous strand of DNA in precise 3-nt increments. Here we discuss an interesting conceptual implication of these results, which is that the recombinases may actively sense and reorganize their alignment register relative to the bound DNA sequences to ensure optimal base triplet pairing interactions during the early stages of recombination.