Kövamees J, Blixenkrone-Möller M, Sharma B, Orvell C, Norrby E
Department of Virology, School of Medicine, Karolinska Institute, Stockholm, Sweden.
J Gen Virol. 1991 Dec;72 ( Pt 12):2959-66. doi: 10.1099/0022-1317-72-12-2959.
The amino acid composition of the two surface proteins of the recently isolated morbillivirus phocid distemper virus (PDV) were deduced from the nucleotide sequence. The fusion (F) protein of PDV exhibited characteristics similar to those of other morbillivirus F proteins. The overall amino acid similarity with its closest homologue, canine distemper virus (CDV), was 72%. From the context of the starting codons and the requirement for a hydrophobic signal peptide, it is likely that translation of the PDV F mRNA starts at the third AUG, corresponding to codon 95 in the long open reading frame of the PDV F gene. After removal of the signal peptide, F0 starts at amino acid 105. From this position the F protein of PDV and CDV exhibit 84% amino acid similarity. The PDV haemagglutinin (H) protein showed 74% amino acid similarity with CDV H protein and highly conserved features responsible for the tertiary structure. Despite these similarities, the two H proteins show marked antigenic differences when probed with monoclonal antibodies. Earlier studies have indicated that rinderpest virus (RPV) is the prototype virus of the morbillivirus genus, from which first CDV/PDV and later measles virus (MV) evolved. From the close relationship shown in this study, it is likely that the divergence of CDV and PDV occurred after MV evolved from RPV.
根据核苷酸序列推导了最近分离出的海豹瘟病毒（PDV）这两种表面蛋白的氨基酸组成。PDV的融合（F）蛋白表现出与其他麻疹病毒F蛋白相似的特征。与其最相近的同源物犬瘟热病毒（CDV）的总体氨基酸相似性为72%。从起始密码子的上下文以及对疏水信号肽的需求来看，PDV F mRNA的翻译很可能起始于第三个AUG，对应于PDV F基因长开放阅读框中的第95个密码子。去除信号肽后，F0从氨基酸105开始。从这个位置起，PDV和CDV的F蛋白氨基酸相似性为84%。PDV血凝素（H）蛋白与CDV H蛋白的氨基酸相似性为74%，且具有负责三级结构的高度保守特征。尽管有这些相似性，但用单克隆抗体检测时，这两种H蛋白显示出明显的抗原差异。早期研究表明，牛瘟病毒（RPV）是麻疹病毒属的原型病毒，CDV/PDV以及后来的麻疹病毒（MV）都由其进化而来。从本研究显示的密切关系来看，CDV和PDV的分化很可能发生在MV从RPV进化之后。
