sentences:  Cdt1 has been shown to associate with the C terminus of Cdc6 to cooperatively promote the association of Mcm proteins to the chromatin.The cryo-EM structure of the OCCM (ORC-Cdc6-Cdt1-MCM) complex shows that the Cdt1-CTD interacts with the Mcm6-WHD.In metazoans, Cdt1 activity during the cell cycle is tightly regulated by its association with the protein geminin, which both inhibits Cdt1 activity during S phase in order to prevent re-replication of DNA and prevents it from ubiquitination and subsequent proteolysis.