Nucleotide sequence of the most abundantly transcribed early gene of human cytomegalovirus strain AD169.

Cytoplasmic poly(A+)RNA was isolated from human embryo fibroblast cells during the early phase of an infection with human cytomegalovirus strain AD169. These preparations contained a single abundant transcript of 2.7 kb which was derived from each of the repeat sequences flanking the long unique region of the virus genome. The gene was unspliced and poly(A+)RNA derived from it continued to accumulate in the cytoplasm of cells during the later stages of infection. This gene and the surrounding region was sequenced. A potential open reading frame of 170 amino acids was identified close to the 5'-terminus of the gene; the 2.7 kb early transcript therefore contains a long untranslated 3'-sequence. The promoter sequences of the 2.7 kb early gene show homology with corresponding regions of the HSV-1 gD and the human hsp 70 genes.