Figure 4. Molecular mechanism of loading the second Cdt1-bound Mcm2–7 hexamer onto origin DNA.
After the formation of OCCM, ORC and Cdc6 dissociate from the C-tier AAA+ side of the loaded Mcm2–7. ORC binds to B2 element of the origin DNA and the N-tier side of the first Mcm2–7, forming the MO complex. Cdc6 next binds to MO to recruit the second Cdt1-bound Mcm2–7, leading to the eventual assembly of the Mcm2–7 double hexamer.
