This set of DNA binding proteins are found exclusively in the archaea and show homology to the origin recognition complex subunit 1/cell division control protein 6 (Orc1/Cdc6) family in eukaryotes. Several members may be found in a genome and interact with each other. The Cdc6/Orc1 protein from the archaeon Pyrococcus furiosus specifically binds to the oriC region. Cdc6 protein is also considerd as replication initiator protein. The number of cdc6 gene copy is highly variable among diffrent archaeal species. In some of archaeal group like Thermococcales cdc6 gene is present in single copy while in others like haloarchaea nd Sulfolobales multiple cdc6 gene copy is present. In some species of Haloarchea and Sulfolobales the cdc6 gene has a close proximity with the Ori sites. In Thermococcales also cdc6 gene shows a close proximity with Ori site. In some archaeal species the number and location of cdc6 gene could be a good indicator for locating Ori sites.

Mini chromosome maintenance complex, or minichromosome maintenance protein complex or mini-chromosome maintenance (MCM) 2-7 helicase complex has a role in both the initiation and the elongation phases of eukaryotic DNA replication, specifically the formation and elongation of the replication fork. MCM is a component of the pre-replication complex, which is a component of the licensing factor. MCM is a hexamer of six related polypeptides (mcm2-7) that form a ring structure

Mini chromosome maintenance complex, or minichromosome maintenance protein complex or mini-chromosome maintenance (MCM) 2-7 helicase complex has a role in both the initiation and the elongation phases of eukaryotic DNA replication, specifically the formation and elongation of the replication fork. MCM is a component of the pre-replication complex, which is a component of the licensing factor. MCM is a hexamer of six related polypeptides (mcm2-7) that form a ring structure