Sequence and expression of the glycoprotein gH gene of pseudorabies virus

In the pseudorabies virus (PrV) genome a gene equivalent to the glycoprotein gH gene of other herpesviruses was identified and sequenced. It is located immediately downstream from the gene encoding PrV thymidine kinase within genomic BamHI fragments 11 and 16. Nucleotide sequencing allowed deduction of the amino acid sequence of gH. The primary translation product is predicted to comprise 686 amino acids and to exhibit a molecular weight of 71.9 kDa. It possess several characteristics typical for membrane glycoproteins, including a N-terminal hydrophobic signal sequence, C-terminal transmembrane and cytoplasmic domains, and domains with high surface probability containing three potential N-linked glycosylation sites. Comparison to other herpesvirus gH proteins revealed amino acid sequence homologies varying from 39% to gH (BHV-1), 28% to gH (HSV-1), and 19% to gH (EBV). Transcriptional analysis revealed a 2.3-kb mRNA as the gH-specific transcript. In vitro translation of either in vitro transcribed or hybrid-selected mRNA confirmed both the location of the gH gene and the size of the gH primary translation product (pgH).