Extended Data Fig. 3.

a, Processing pipeline of the DH in absence of ORC6 dataset. 5,158 movies yielded a 4.1 Å structure following 2D and 3D classification in cryoSPARC. b, A cut-through view of the hDH -ORC6 overlayed with the high resolution hDH +ORC6 structure from this study highlighting the same untwisted DNA at the homo-dimerization interface. c, A cut-through view of the hDH -ORC6 overlayed with and coloured by the PDB model of hDH +ORC6 including a zoom-in view showing the untwisted DNA at the homo-dimerization interface. d, Benzonase footprinting experiment with MCM5 mutants that were tested using FL + ORC6 loading conditions. After 30 min of MCM loading, benzonase was added at twice the normal concentration for 0.5 min.e, Processing pipeline of MCM5 AG double hexamer sample. 13,203 acquired movies yielded a 5.56 Å structure following multiple rounds of 2D cleaning and 3D classification in RELION and cryoSPARC.