Fig. 3.

Interaction of MSH2 or MSH6 with ATR and SMC1. (A) In vitro interactions of MSH2 or MSH6 with ATR and SMC1, respectively. Affinity-purified human MSH2 and MSH6 from sf9 cells were incubated with purified Flag-ATR or ³⁵S-labeled, in vitro translated SMC1. An unrelated antibody incubated with sf9 cell lysate was used as a control. Coomassie blue staining of the membrane after Western blotting shows that human MSH2 and MSH6 used in the binding reactions do not copurify with the insect MSH6 or MSH2. (B) MSH6-independent association of MSH2 and ATR. IPs were carried out in NE prepared from lymphoblastoid cell line TK6, which expresses wild-type MSH6, and MT1, which expresses a low level of a mutant form of MSH6.