Identification of the coding sequence for herpes simplex virus uracil-DNA glycosylase.

We have recently isolated a herpes simplex virus (HSV) type 2 (strain 333)-specific cDNA that encodes uracil-DNA glycosylase. This cDNA lies between 0.065 and 0.08 map units on the HSV genome. Within this region there are five overlapping transcripts which encompass three open reading frames. We have determined that the second open reading frame, UL-2, codes for glycosylase. In vitro transcription of the UL-2 region and subsequent translation yielded uracil-DNA glycosylase activity. Sequence analysis of the UL-2 open reading frame indicated a coding capacity of 295 amino acids. Comparison to the HSV type 1 (strain 17) sequence indicated that there is 74% amino acid homology between the two strains, with most of the conservation occurring in the middle and the 3' end. The 5' end, however, has diverged considerably.