1型鸭肝炎病毒衣壳蛋白的分子特征

Molecuar characteristics of capsid proteins of duck hepatitis virus 1

本研究测定了2株1型鸭肝炎病毒(DHV-1)的衣壳蛋白编码区序列,并将推导的氨基酸序列与其他小RNA病毒衣壳蛋白的氨基酸序列进行了比较分析。结果显示,DHV仅编码3种衣壳蛋白,3种衣壳蛋白中均存在类似于其他小RNA病毒的核心结构,即八链反向平行β桶结构。DHV-1与其他小RNA病毒之间衣壳蛋白的氨基酸序列差异主要位于VP1的两端、VP3的N端以及连接β链的环,特别是βB-C、βE-F及βG-H环的序列差异更为显著。与9个属小RNA病毒P1蛋白的比较结果表明,DHV-1与双埃柯病毒属的成员具有相近的遗传关系,但在P1进化树中,DHV-1形成一个独立的分支,故应在小RNA病毒科中为该病毒成立一个新属。

The sequence of capsid protein encoding region was determined for two duck hepatitis virus 1 （DHV-1） isolates in this study. The deduced amino acid sequences from the capsid protein encoding region of DHA-1s were compared with those of other picornaviruses. The result indicated that only three capsid proteins are encoded by DHV-1s, and that all the three capsid proteins of DHV-1s contain the basic core structure, an eight-stranded antiparallel β-barrelas seen in other picornaviruses. The difference between DHV-1s and other picornaviruses are concentrated in the two termini of VP1 and the N-terminal of VP3 and the loops linking predicted β sheets, particularly βB-C, βE-F, and βG-H loops. Compared to other picornaviruses, DHV-1s exhibit a closest genetic relationship to the members of the genus Parechovirus. However, DHV-1 strains formed a separate branch in the phylogenetic tree based on P1 proteins. It is proposed that DHV should be assigned to a new genus in the family Picornaviridae.