– Plays an essential role in the initiation of viral DNA synthesis. Binds specifically to an inverted terminal repeat element (ITR) on the 3′ and 5′ ends of the viral DNA, where it cleaves a site specifically to generate a priming site for initiation of the synthesis of a complementary strand. Plays also a role as transcriptional regulator, DNA helicase and as key factors in site-specific integration of the viral genome. Regulates host PKA activity by interacting with host PRKX as a mechanism of interfering with helper virus propagation and promoting its own replication. Inhibits the host cell cycle G1/S, S and G2/M transitions. These arrests may provide essential cellular factors for viral DNA replication.