sentences:  A mutation in any one of the six Mcm proteins reduces the conserved ATP binding sites, which indicates that ATP hydrolysis is a coordinated event involving all six subunits of the Mcm complex.Studies have shown that within the Mcm protein complex are specific catalytic pairs of Mcm proteins that function together to coordinate ATP hydrolysis.For example, Mcm3 but not Mcm6 can activate Mcm6 activity.