Characterization of the gene encoding herpesvirus of turkeys gp57-65: comparison to Marek's disease virus gp57-65 and herpes simplex virus glycoprotein C.
A gene encoding herpesvirus of turkeys (HVT) strain FC 126 gp57-65 has been mapped to the viral genome and sequenced. The HVT (FC 126) gp57-65 gene maps to BamHI fragments K1 and M, colinear with the gene from Marek's disease virus (MDV) strain GA. HVT gp57-65 gene sequences were compared to the MDV strain GA gp57-65 gene that we sequenced previously. Overall, the two sequences are 66% identical, with greater similarity in the 3' proximal two thirds of the genes. HVT gp57-65 gene sequences have a slightly higher overall guanosine plus cytosine (G + C) content than MDV gp57-65 gene sequences (46% vs. 41%, respectively). A single, long open reading frame capable of encoding 523 amino acids was identified within the HVT gp57-65 gene region. The predicted precursor polypeptide derived from this open reading frame would have a calculated molecular weight of 58,587. The predicted HVT gp57-65 amino acid sequences contain six potential N-linked glycosylation sites (asn-x-ser/thr). Five of these six potential N-linked glycosylation sites are conserved between the HVT and MDV predicted amino acid sequences. Hydropathic analysis of the predicted HVT gp57-65 amino acid sequences indicate the presence of an amino-terminal hydrophobic sequence, which may function as a signal peptide, and a hydrophobic carboxyl terminal sequence, which may function as a membrane anchor sequence. Overall, MDV gp57-65 and HVT gp57-65 precursor polypeptide sequences are 73% homologous and share many potential antigenic epitopes. Predicted MDV and HVT gp57-65 protein sequences are similar to those of herpes simplex virus glycoprotein C (gC) and gC-like proteins from other herpes-viruses. Similarities are scattered throughout the molecule, with a primary concentration near the carboxyl half of the molecule. One stretch of 60 amino acids (HVT amino acids 378-437 and MDV amino acids 350-410) are relatively well conserved among gC-like proteins from six herpesviruses. The possible implications of these homologies and the potential roles of gC-like proteins in virus infection, growth, and replication are discussed.
Coussens
P M
PM
Department of Animal Science, Michigan State University, East Lansing 48824.
Wilson
M R
MR
Camp
H
H
Roehl
H
H
Isfort
R J
RJ
Velicer
L F
LF
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics*; D001483:Base Sequence; D002478:Cells, Cultured; D005814:Genes, Viral; D006023:Glycoproteins / Q000235:genetics*; D006564:Herpesviridae / Q000235:genetics*; D008381:Herpesvirus 2, Gallid / Q000235:genetics; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D018139:Simplexvirus / Q000235:genetics; D014422:Turkeys; D014759:Viral Envelope Proteins / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*
D000956:Antigens, Viral; D006023:Glycoproteins; C056151:Marek's disease herpesvirus gp57-65; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C038535:glycoprotein gC, herpes simplex virus type 1; C064439:herpesvirus protein gp57-65