Fig. 2.

Patch test for MLH1 and PMS1 mutations affecting interface residues. A. Patches of a mlh1Δ strain transformed with a wild-type MLH1 plasmid, an empty plasmid, or a plasmid carrying a mlh1 interface mutation were replica plated onto CSM-Thr and CSM-Lys plates to test for reversion of the hom3–10 and lys2–10A frameshift mutations, respectively. Growth indicates increased mutation rates. B. Patches of a pms1Δ strain transformed with a wild-type PMS1 plasmid, an empty plasmid, or a plasmid carrying various pms1 interface mutations were tested as in panel A above.