FIG. 5.

Model of how MutS2 might limit intergenomic recombination. A. RecA-mediated strand invasion of donor DNA, which is essential for recombination events, forms a D-loop. B. MutS2, shown as a dimer via interaction at its ATPase/dimerization domains (thick gray lines), recognizes the primary recombination structure via its DNA association domains (thin gray lines). C. SMR endonuclease activity (represented in black) introduces a nick into the DNA. D. Recruitment of other proteins, possibly a repair polymerase such as PolA, with exonuclease activity, removes the invading DNA and fills in the gap. E. Restoration of original dsDNA.