In vitro transcription and translation of proteins encoded by the BamHI-B genomic fragment of herpes simplex virus-1.

The BamHI-B DNA fragment of herpes simplex virus type-1 (HSV-1) is associated with intraperitoneal pathogenicity. Among the recently mapped RNA transcripts from this fragment (15), one was reported to be associated with latency. To relate the RNA transcripts to virus pathogenicity, the in vitro-transcribed RNAs from BamHI-B fragments of three HSV-1 strains--F (pathogenic), R19, and HFEM (apathogenic), were studied by in vitro translation. When the BamHI-HpaI (0.738-0.755 map units) DNA fragment from HSV-1 strain F was transcribed rightward and translated, three proteins of 70, 63, and 51 kD were detected. The 63 kD protein resembles in size and orientation the protein encoded by the ICP-27 (IE-2) gene (0.740-0.749 mu). The 51 kD polypeptide is assumed to be a prematurely terminated form of this protein. No proteins were obtained from RNA transcribed in the opposite direction. The SalI-NcoI (0.746-0.761 mu) fragment of the three HSV-1 strains yielded two proteins of 25 and approximately 15 kD when transcribed rightward and a 35 kD polypeptide from RNA transcribed in the opposite direction. As a result of the genomic deletion in HFEM, it was possible to obtain the 35 kD protein from the SalI-SalI DNA fragment (0.746-0.761 mu) as well. In vitro transcription and translation of the PstI-SalI (0.778-0.790 mu) DNA fragment (the right-hand side of HpaI-P) did not result in protein synthesis. The possibility that the UL56 gene is connected with the intraperitoneal pathogenicity of HSV-1 is discussed.