Epstein-Barr virus DNA polymerase (EBV DNA polymerase)

The Epstein-Barr virus (EBV) DNA polymerase, specifically the catalytic subunit encoded by the BALF5 gene, is an essential enzyme for the replication of the viral genome during the lytic cycle (UniProt: P03198). It functions as a DNA-directed DNA polymerase that synthesizes viral DNA by incorporating deoxynucleoside triphosphates (dNTPs) into the nascent strand (PubMed: 10823897). EBV is a gammaherpesvirus linked to various diseases, including infectious mononucleosis, Burkitt lymphoma, and nasopharyngeal carcinoma (NIH: National Cancer Institute). The enzyme is a major target for antiviral drugs such as ganciclovir, foscarnet, and cidofovir, which act as competitive inhibitors or chain terminators (DrugBank: DB00449). While effective during active lytic replication, these inhibitors do not eliminate the virus during its latent phase, as the virus then relies on host cell DNA polymerase delta for maintenance (PubMed: 15141010). Clinical challenges include drug-induced toxicities like myelosuppression and the emergence of resistance mutations within the BALF5 gene (PubMed: 22438452).

Other names

BALF5DNA-directed DNA polymeraseEBV PolEpstein-Barr virus catalytic subunit of DNA polymerase

Inhibition of viral DNA synthesis through competitive inhibition of deoxyribonucleotide triphosphate (dNTP) binding or incorporation into the nascent DNA chain leading to chain termination (DrugBank: DB00449).