The Nucleotide Sequence of an Equine Herpesvirus 4 Gene Homologue of the Herpes Simplex Virus 1 Glycoprotein H Gene

Abstract

The equine herpesvirus 4 (EHV-4) gene glycoprotein H (gH) gene homologue was localized by virtue of the conserved genomic position of this gene throughout members of the herpesvirus family. The gene maps immediately downstream of the the thymidine kinase gene at approximately 0.49 to 0.51 map units within genomic fragment BamHI C. The EHV-4 gH primary translation product is predicted to be a polypeptide of Mr 94 100, 855 amino acid long, which possesses features characteristic of a membrane glycoprotein, namely an N-terminal signal sequence, a large hydrophilic domain containing 11 putative N-linked glycosylation sites, a C-terminal transmembrane domain, and a charged cytoplasmic tail. Comparision to other herpesvirus glycoproteins revealed identifies of 85%, 26% and 32% with the gH counterparts of the alphaherpesviruses EHV-1, herpes simplex virus 1 and varicella-zoster, respectively, and of 17% and 18% with those of human cytomegalovirus, herpesvirus saimiri and Epstein-Barr virus. The EHV-4 gH exhibites features previously reported to be conserved throughout the gH polypeptides of herpesviruses of all three subgroups. A region of direct repeat elements and a possible origin of DNA replication are located immediately downstream of the gH gene.