Epstein-Barr virus DNA polymerase (BALF5) (BALF5)

The Epstein-Barr virus (EBV) DNA polymerase is an essential enzyme for the lytic replication of the EBV genome [3, 5]. Encoded by the BALF5 gene, it functions as the catalytic subunit of the viral DNA replication complex, working alongside the processivity factor BMRF1 to synthesize viral DNA [3, 8]. While EBV typically persists in a latent state, its transition to the lytic cycle is necessary for the production of infectious progeny and is implicated in the development of EBV-associated malignancies such as nasopharyngeal carcinoma, Burkitt lymphoma, and post-transplant lymphoproliferative disorders [1, 7, 13]. This enzyme is a primary target for several antiviral drugs, including nucleoside and nucleotide analogs like ganciclovir, foscarnet, and cidofovir [1, 13]. These agents act by competing with natural deoxynucleoside triphosphates for binding to the polymerase or by causing premature termination of the growing DNA chain [1, 10]. Despite their efficacy in reducing viral load, the use of these inhibitors is often limited by significant side effects such as nephrotoxicity and bone marrow suppression, as well as the potential for the emergence of drug-resistant mutations in the BALF5 gene [4, 13]. Recent studies have also identified tenofovir prodrugs as potent inhibitors of EBV DNA polymerase, offering potential new avenues for prophylaxis and treatment [4, 7].

Other names

BALF5DNA polymerase catalytic subunitEBV DNA polymeraseEpstein-Barr virus DNA-directed DNA polymerase

Competitive inhibition of viral DNA polymerase and DNA chain termination