Replicates viral genomic DNA in the late phase of lytic infection, producing long concatemeric DNA. The replication complex is composed of six viral proteins: the DNA polymerase, processivity factor, primase, primase-associated factor, helicase, and ssDNA-binding protein (By similarity). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Forms a complex with the major DNA-binding protein BALF2, the DNA polymerase processivity factor BMRF1, and the alkaline exonuclease BGLF5. Interacts with the putative helicase-primase complex composed of BBLF4, BSLF1 and BBLF2/3 proteins; these interactions may coordinate leading and lagging strand DNA synthesis at the replication fork (By similarity). the protein is present at discrete sites in nuclei, called replication compartments where viral DNA replication occurs. Belongs to the DNA polymerase type-B family.