Mutants of herpes simplex virus types 1 and 2 that are resistant to phosphonoacetic acid induce altered DNA polymerase activities in infected cells.

Three mutants of herpes simplex virus (HSV) have been isolated which form plaques in the presence of 100 mug/ml phosphonoacetic acid (PPA). All three mutants (3 from HSV-1 strain 17 syn+, 14 from HSV-1 strain 17 syn, and 19 from HSV-2) induce viral DNA synthesis and viral DNA polymerase activity, and these are much less sensitive to PPA than the wild-type virus. The results support the hypothesis that PPA interacts directly with the viral DNA polymerase protein, at least part of which is virus coded.