MutS?. MSH2 has two interacting domains with MSH6 in the MutS? heterodimer, a DNA interacting domain, and an ATPase domain.

The MutS? dimer scans double stranded DNA in the nucleus, looking for mismatched bases. When the complex finds one, it repairs the mutation in an ATP dependent manner. The MSH2 domain of MutS? prefers ADP to ATP, with the MSH6 domain preferring the opposite. Studies have indicated that MutS? only scans DNA with the MSH2