Functions as a docking protein to recruit essential components of the viral replication machinery to viral DNA origins. In the presence of the major DNA-binding protein, opens dsDNA leading to a conformational change in the origin that facilitates DNA unwinding and subsequent replication. Homodimer. Interacts with the major DNA-binding protein ICP8. Interacts with the helicase/primase component UL8 and the polymerase accessory protein UL42 (By similarity). Belongs to the herpesviridae OriBP family.