Branch migration of RuvA-RuvB in solution. The four monomers of RuvA combine around a central pen to accommodate the square planar configuration of the Holliday junction in which the four DNA duplex arms attach to grooves on the concave surface of RuvA. Through ATP hydrolysis, the two hexameric RuvB rings encircle and translocate the dsDNA arms. Curved arrows indicate rotation of DNA while the thick arrows indicate translocation of dsDNA through the junction. DNA rotation during Holliday junction branch occurs at a V(max) of 1.6 revolutions per second, or 8.3 bp per second. (Adopted from reference  with the permission from the publisher).