Fig. 3: Comparison between ATPĪ³S-OCCM and OCCMMcm2RA structures.
From: Unidirectional MCM translocation away from ORC drives origin licensing
a Side views of the two OCCM structures highlight structural changes in ORC-Cdc6 and at the interface with MCM. In OCCMMcm2RA (right, cryo-EM density) Cdc6 and the C-terminal cyclin box domain become flexible, and the Orc2 WHD domain becomes disordered, compared to ATPĪ³S-OCCM (left, surface representation). The Mcm3 WHD domain that contacts Cdc6 and Orc1 also becomes disordered in OCCMMcm2RA. b MCM ATPase view shows that the Mcm2-5 gate is notched in ATPĪ³S-OCCM (top) and closed in OCCMMcm2RA (bottom). ATPĪ³S is bound at four inter-subunit sites in ATPĪ³S-OCCM. Instead, ADP is found engaged at all sites in OCCMMcm2RA. c N-terminal MCM view shows that the Mcm2-5 gate is notched in ATPĪ³S-OCCM (top) and closed in OCCMMcm2RA (bottom). The B-domain of Mcm2 that plugs the MCM pore in ATPĪ³S-OCCM (top, surface representation) is reconfigured so that duplex DNA can be fully loaded in OCCMMcm2RA (bottom, cryo-EM density). d Cut-through side view shows that duplex DNA traverses ORC-Cdc6 and the MCM ATPase in ATPĪ³S-OCCM (top, surface representation), while it spans the entire length of the MCM hexamer in OCCMMcm2RA (bottom, cryo-EM density).
