Nucleotide sequencing of the fusion protein (F) gene of phocid distemper virus-2 (PDV-2), recently isolated from Baikal seals (Phoca sibirica), revealed an open reading frame (nucleotides 84 to 2075) with two potential in-frame ATG translation initiation codons. We suggest that the second in-frame ATG triplet at positions 264 to 266 initiates the translation, resulting in a protein of 537 amino acid residues with a calculated M(r) of 63,035. The putative F1/F2 cleavage site, located approximately 100 amino acid residues from the N terminus, is identical to those of the F proteins of phocid distemper virus-1 (PDV-1) isolated from European harbour seals (Phoca vitulina) and of canine distemper virus (CDV). A full scale comparison of morbillivirus F genes reveals that the conserved F0 extracellular protein-encoding region contains a large number of non-expressed mutations, suggesting that this part of the protein is under strong functional constraints. Phylogenetic analysis of morbillivirus F gene nucleotide sequences revealed a closer evolutionary relationship between PDV-2 and CDV than between PDV-1 and PDV-2. These data were supported by cross-reactivity patterns of PDV-2 and CDV obtained with monoclonal antibodies to structural proteins of PDV-1 and CDV, and suggest that PDV-2 is a strain of CDV, resulting from a trans-species infection.

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Keywords *Genes, Viral, *Phylogeny, 0 (Codon), 0 (DNA, Viral), 0 (RNA, Messenger), 0 (Viral Fusion Proteins), 149346-80-5 (F protein, Phocine distemper virus), Amino Acid Sequence, Animals, Base Sequence, Codon/genetics, DNA, Viral/genetics, Distemper Virus, Canine/*genetics, Measles virus/*genetics, Molecular Sequence Data, Molecular Weight, Paramyxoviridae/*genetics/isolation & purification, RNA, Messenger/genetics, Seals, Sequence Homology, Amino Acid, Sequence Homology, Nucleic Acid, Viral Fusion Proteins/biosynthesis/*genetics/isolation & purification
Persistent URL hdl.handle.net/1765/3480
Citation
Visser, I.K.G., van der Heijden, R.W.J., van de Bildt, M.W.G., Kenter, M.J.H., Örvell, C., & Osterhaus, A.D.M.E.. (1993). Fusion protein gene nucleotide sequence similarities, shared antigenic sites and phylogenetic analysis suggest that phocid distemper virus 2 and canine distemper virus belong to the same virus entity.. Journal of General Virology, 74, 1989–1994. Retrieved from http://hdl.handle.net/1765/3480