Branch migration

Branch migration describes the ability of a DNA strand partially paired with its complement in a duplex to extend its pairing by displacing the resident strand with which it is homologous. This usually happens when two homologous double strands form a Holliday junction and the whole structure slides into one direction; the "branch migrates". This procedure can influence the amount of information that is transferred between two recombining partners. In E. Coli RuvA and RuvB of the RuvABC protein complex promote branch migration until RuvC binds and resolves the Holliday junction by cleaving. Another definition for branch migration is the extension of a D-loop when a single stranded DNA strand invades a "recipient" duplex during recombination or repair.