DNA sequence of the herpes simplex virus type 1 gene whose product is responsible for transcriptional activation of immediate early promoters

Previous work has shown that transcriptional activation of herpes simplex virus type 1 (HSV-1) immediate early genes is mediated by a protein species (Vmw65) present in the tegument of infecting virions. This paper describes DNA sequence analysis and mRNA mapping of the Vmw65 gene in HSV-1 strain 17. The Vmw65 coding region was identified as a 490 codon sequence encoding a polypeptide of molecular weight 54,342 and characterised by a high proportion of charged amino acid residues. A homologue to Vmw65 was detected in the genome of varicella-zoster virus, another human herpesvirus. Apart from its role in trans-activation, Vmw65 is a major constituent of the virion. Its possible significance in virus structure is discussed.