While the interaction between CDT1 and the MCM2-7 complex was confirmed in human (Wu et al. 2014) and other mammalian cells (Cook et al. 2004), as well as in the fruit fly (Costa et al. 2011), the mechanism of interaction has only been studied in detail in yeast. From yeast studies, CDT1 binds to the MCM2-7 complex by interacting with its MCM2 and MCM6 subunits (Kawasaki et al. 2006; Remus et al. 2009), resulting in the formation of a hetero-heptameric CDT1:MCM2-7 complex (Sun et al. 2013). CDT1 binding relieves the autoinhibitory action of the MCM6 subunit that prevents association of the MCM2-7 complex with the complex of ORC and CDC6 in the absence of CDT1 (Fernández-Cid et al. 2013, Sun et al. 2013).