DNA polymerase catalytic subunit (UL30) (UL30)

The DNA polymerase catalytic subunit (UL30) is an essential enzyme for the replication of the herpes simplex virus (HSV) genome during the lytic phase of infection [1.1.1, 1.3.1]. As a member of the Family B DNA polymerases, it exhibits multiple catalytic activities, including 5'-3' DNA-directed DNA polymerase activity, 3'-5' proofreading exonuclease activity, and ribonuclease H activity [1.1.2, 1.3.2]. UL30 functions as part of a larger replication complex, most notably forming a high-affinity heterodimer with the processivity factor UL42, which enhances the enzyme's ability to synthesize long DNA strands without dissociating [1.1.4, 1.4.1]. This enzyme is the primary therapeutic target for most anti-herpetic medications, including nucleoside analogs like acyclovir and pyrophosphate analogs like foscarnet [1.2.1, 1.2.3]. These drugs disrupt viral replication by either causing premature chain termination or by directly inhibiting the polymerase's active site [1.2.1, 1.2.3]. However, the clinical utility of these agents is often limited by the emergence of drug-resistant viral strains, which typically harbor specific point mutations within the UL30 gene, particularly in immunocompromised populations [1.1.2, 1.3.4].

Other names

pUL30HSV-1 DNA polymeraseHSV-2 DNA polymerasePolDNA-directed DNA polymeraseUL30 gene product

Nucleoside analogs (e.g., acyclovir) act as competitive inhibitors of the viral DNA polymerase and cause premature DNA chain termination upon incorporation. Pyrophosphate analogs (e.g., foscarnet) bind to the pyrophosphate binding site of the polymerase, blocking the cleavage of pyrophosphate from deoxynucleotide triphosphates and halting DNA chain elongation.