Identification of the herpes simplex virus type 1 gene encoding the dUTPase.

The dUTPase gene of herpes simplex virus has been identified using a novel approach. The upstream regulatory sequences, or the promoter and upstream regulatory sequences, of the immediate-early gene Vmw175 (ICP4) were inserted in front of genes mapping in the region 0.69 to 0.70 map units of the virus genome to enhance transient gene expression in a transfection assay. One clone, containing a gene specifying a 1.5-kb mRNA, induced significant amounts of virus-specific dUTPase activity. The enzyme activity was abolished by insertion of a HindIII linker into the KpnI site within the coding sequences of this gene. The results show that the enzyme is virus coded and that 1.5-kb mRNA specifies the dUTPase.