FIGURE 5-40 Recombinational repair of a collapsed replication fork. Parent strands are light and dark blue. The leading daughter strand is dark red, and the lagging daughter strand pink. Diagonal lines in step 3 and beyond represent a single phosphodiester bond from the DNA strand of the corresponding color. Small black arrows following step 4 represent cleavage of the phosphodiester bonds at the crossover of DNA strands in the Holliday structure. See http://www.sheffield.ac.uk/mbb/ruva for an animation of branch migration catalyzed by E. coli proteins RuvA and RuvB. See the text for a discussion.