IDENTIFICATION AND TRANSCRIPTIONAL ANALYSIS OF A 3'-COTERMINAL GENE-CLUSTER CONTAINING UL1, UL2, UL3, AND UL3.5 OPEN READING FRAMES OF BOVINE HERPESVIRUS-1

We have identified and sequenced 3113 nucleotides located at the right end of the HindIII L fragment of the bovine herpesvirus-1 genome from map units 0.712 to 0.734. Analysis of the sequence identified four op en reading frames (ORFs) which are designated UL1, UL2, UL3, and UL3.5 based on their homology with proteins of herpes simplex virus-1 (HSV- 1), pseudorabies virus (PRV), equine herpesvirus-1, and varicella-zost er virus. The UL1 ORF of 158 amino acids exhibits limited homology wit h UL1 (glycoprotein gL) of HSV-1 (27%) and PRV (21%). The UL2 ORF of 2 04 amino acids shows significant homology to UL2 (uracil-DNA glycosyla se) of HSV-1 (68%) and PRV(75%). The UL3 ORF of 204 amino acids shows significant homology to UL3 (nuclear phosphoprotein) of HSV-1 (62%) an d PRV (53%). The UL3.5 ORF of 126 amino acids shows limited homology t o the UL3.5 ORF of PRV (31%). The homolog of this gene is absent in HS V-1. Nucleotide sequence analyses also revealed potential TATA boxes l ocated upstream of each ORF. However, only one polyadenylation signal was detected downstream of the UL3.5 ORF. Northern (RNA) blot analyses revealed four transcripts of 2.4, 1.9, 1.3, and 0.7 kb, which are tra nscribed in the same direction and are 3'-coterminal transcripts. Thes e mRNAs appear to yield proteins encoded by UL1 (2.4 kb), UL2 (1.9 kb) , UL3 (1.3 kb), and UL3.5 (0.7 kb) ORFs. (C) 1995 Academic Press, Inc.