Both Orc1 and Orc5 bind ATP, though only Orc1 has ATPase activity. The binding of ATP by Orc1 is required for ORC binding to DNA and is essential for cell viability. The ATPase activity of Orc1 is involved in formation of the pre-RC. ATP binding by Orc5 is crucial for the stability of ORC as a whole. Only the Orc1-5 subunits are required for origin binding; Orc6 is essential for maintenance of pre-RCs once formed. Interactions within ORC suggest that Orc2-3-6 may form a core complex.
^ abcMatsuda K, Makise M, Sueyasu Y, Takehara M, Asano T, Mizushima T (December 2007). "Yeast two-hybrid analysis of the origin recognition complex of Saccharomyces cerevisiae: interaction between subunits and identification of binding proteins". FEMS Yeast Res. 7 (8): 1263–9. PMID17825065. doi:10.1111/j.1567-1364.2007.00298.x.
^ abBell SP, Stillman B (May 1992). "ATP-dependent recognition of eukaryotic origins of DNA replication by a multiprotein complex". Nature. 357 (6374): 128–34. PMID1579162. doi:10.1038/357128a0.
^ abBell SP, Mitchell J, Leber J, Kobayashi R, Stillman B (November 1995). "The multidomain structure of Orc1p reveals similarity to regulators of DNA replication and transcriptional silencing". Cell. 83 (4): 563–8. PMID7585959. doi:10.1016/0092-8674(95)90096-9.
^ abcGibson DG, Bell SP, Aparicio OM (June 2006). "Cell cycle execution point analysis of ORC function and characterization of the checkpoint response to ORC inactivation in Saccharomyces cerevisiae". Genes Cells. 11 (6): 557–73. PMID16716188. doi:10.1111/j.1365-2443.2006.00967.x.
^Klemm RD, Austin RJ, Bell SP (February 1997). "Coordinate binding of ATP and origin DNA regulates the ATPase activity of the origin recognition complex". Cell. 88 (4): 493–502. PMID9038340. doi:10.1016/S0092-8674(00)81889-9.
Bell, Stephen P.; Dutta, Anindya (July 2002). "DNA Replication in Eukaryotic Cells". Annual Review of Biochemistry. Annual Reviews. 71: 333–374. doi:10.1146/annurev.biochem.71.110601.135425. A comprehensive review of molecular DNA replication