Component of the origin recognition complex (ORC) that binds origins of replication. DNA-binding is ATP-dependent. The specific DNA sequences that define origins of replication have not been identified yet. ORC is required to assemble the pre-replication complex necessary to initiate DNA replication (By similarity). Component of ORC, a complex composed of at least 6 subunits: ORC1, ORC2, ORC3, ORC4, ORC5 and ORC6. ORC is regulated in a cell-cycle dependent manner. It is sequentially assembled at the exit from anaphase of mitosis and disassembled as cells enter S phase (By similarity). Interacts with CDC6 and KAT7/HBO1 (By similarity). Interacts with LRWD1 predominantly during the G1 phase and with less affinity during mitosis, when phosphorylated (By similarity). Phosphorylated during mitosis. Belongs to the ORC1 family.