Based on Schmutte et. al. 31. The C-terminus of hMLH1 is required for interaction with the N-terminus of hMSH3 (yellow rectangle and lines). This region of hMLH1 is also required for its interaction with hEXOI and heterodimer formation with hMLH3, hPMS1, and hPMS2 28, 31, 37. In addition, the N-terminal region of hMSH3 required for interaction with hMLH1 includes the interaction regions of hMSH3 with hMSH2 and hEXOI 29, 31.