Acts as a primer for viral genomic replication. DNA terminal protein is covalently linked to the 5'-ends of both strands of the genome through a phosphodiester bond between the beta-hydroxyl group of a tyrosine residue and the 5'-phosphate of the terminal deoxythymidylate. This protein is essential for DNA replication and is involved in the priming of DNA elongation. Interacts with the DNA-binding protein P1.