description
DNA replication pre-initiation in eukaryotic cells begins with the formation of the pre-replicative complex (pre-RC) during the late M phase and continues in the G1 phase of the mitotic cell cycle, a process also called DNA replication origin licensing. The association of initiation proteins (ORC, Cdc6, Cdt1, Mcm2-7) with the origin of replication in both S. cerevisiae and humans has been demonstrated by chromatin immunoprecipitation experiments. In S. cerevisiae, pre-replicative complexes are assembled from late M to G1. In mammalian cells as well, pre-replicative complexes are assembled from late M to G1, as shown by biochemical fractionation and immunostaining. There are significant sequence similarities among some of the proteins in the pre-replicative complex. The ORC subunits Orc1, Orc4 and Orc5 are homologous to one another and to Cdc6. The six subunits of the Mcm2-7 complex are homologous to one another. In addition, Orc1, Orc4, Orc5, Cdc6, and the Mcm2-7 subunits, are members of the AAA+ superfamily of ATPases. Since the initial identification of these pre-RC components other factors that participate in this complex have been found, including Cdt1 in human, Xenopus, S. pombe, and S. cerevisiae cells

external resources
NCBI:1269833
REACTOME:R-HSA-68867
PUBMED:11801723
PUBMED:9829972
PUBMED:9288745
PUBMED:9407030
PUBMED:9927482
PUBMED:9335335
PUBMED:11046155

genes
CDC6 , E2F1 , E2F2 , E2F3 , MCM2 , MCM3 , MCM4 , MCM5 , MCM6 , MCM7 , ORC1 , ORC2 , ORC4 , ORC5 , PSMA1 , PSMA2 , PSMA3 , PSMA4 , PSMA5 , PSMA6 , PSMA7 , PSMB1 , PSMB2 , PSMB3 , PSMB4 , PSMB5 , PSMB6 , PSMB7 , PSMB8 , PSMB9 , PSMB10 , PSMC1 , PSMC2 , PSMC3 , PSMC4 , PSMC5 , PSMC6 , PSMD1 , PSMD2 , PSMD3 , PSMD4 , PSMD5 , PSMD7 , PSMD8 , PSMD9 , PSMD10 , PSMD11 , PSMD12 , PSMD13 , PSME1 , PSME2 , RPS27A , UBA52 , UBB , UBC , SEM1 , PSMF1 , PSMD6 , PSME3 , PSMD14 , PSME4 , ORC6 , ORC3 , GMNN , CDT1 , MCM8 , PSMB11 , PSMA8 , C7orf76 , LOC100506136 ,