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 ssDNA-binding protein UL57, the DNA polymerase processivity factor UL44, and the alkaline exonuclease UL98. Interacts with the putative helicase-primase complex composed of UL70, UL102 and UL105 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.