Hemagglutinin-esterase: A novel structural protein of torovirus
Hemagglutinin-esterase: A novel structural protein of torovirus
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DOI：
10.1128/jvi.71.7.5277-5286.1997
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发表时间：
1997-07-01
影响因子：
5.4
通讯作者：
deGroot, RJ
中科院分区：
文献类型：
--
作者：
Cornelissen, LAHM;Wierda, CMH;deGroot, RJ
我们对牛圆环病毒（BoTV）布雷达株基因组的3 '端3 kb进行了表征。一个新的1.2 kb的基因，位于膜和核衣壳蛋白的基因之间，被确定。该基因的最3 '端0.5kb也存在于马圆环病毒分离株伯尔尼病毒（BEV）的基因组中，编码与冠状病毒和C型流感病毒的血凝素酯酶（HE）具有30%序列同一性的I类膜蛋白。BoTV HE基因的异源表达产生了65，000分子量的N-糖基化蛋白，其显示乙酰酯酶活性。血清学证据表明，HE同源物在自然感染过程中表达，并代表一种突出的抗原。通过使用针对HE残基13至130的抗血清，在放射性碘标记的蔗糖梯度纯化的BoTV制剂中检测到HE蛋白。HE是一种结构蛋白的正式证据是通过免疫电镜提供的。除了17至20 nm的大尖峰外，BoTV病毒粒子还具有较短的表面突起（平均6 nm）。我们假设，这些表面的投影，这是从BEV病毒粒子缺席，是由BoTV HE同系物。BE基因？现在已经在三种不同的病毒属中得到证实，是模块化进化的一个典型例子。
We have characterized the 3'-most 3 kb of the genome of bovine torovirus (BoTV) strain Breda. A novel 1.2-kb gene, located between the genes for the membrane and nucleocapsid proteins, was identified. This gene, the 3'-most 0.5 kb of which is also present in the genome of the equine torovirus isolate Berne virus (BEV), codes for a class I membrane protein displaying 30% sequence identity with the hemagglutinin-esterases (HEs) of coronaviruses and influenza C viruses. Heterologous expression of the BoTV HE gene yielded a 65,000-molecular weight N-glycosylated protein displaying acetylesterase activity. Serologic evidence indicates that the HE homolog is expressed during the natural infection and represents a prominent antigen. By using an antiserum raised against residues 13 to 130 of HE, the HE protein was detected in radioiodinated, sucrose gradient-purified BoTV preparations. Formal evidence that HE is a structural protein was provided by immunoelectron microscopy. In addition to the large, 17- to 20-nm spikes, BoTV virions possess shorter surface projections (6 nm on average). We postulate that these surface projections, which are absent from the BEV virion, are composed of the BoTV HE homolog. The BE gene? which has now been demonstrated in three different virus genera, is a showpiece example of modular evolution.