The enhanced DNA replication fidelity of a mutant herpes simplex virus type 1 DNA polymerase is mediated by an improved nucleotide selectivity and reduced mismatch extension ability.

We previously demonstrated that a recombinant herpes simplex virus containing a mutation within the finger domain of DNA polymerase replicated DNA with increased fidelity. In this study, we demonstrate that, compared with wild-type polymerase, the mutant enzyme exhibited improved nucleotide selectivity and a reduced ability to extend from mismatched primer termini, which would contribute to the increased DNA replication fidelity.