3-DIMENSIONAL STRUCTURE OF CALICIVIRUS
3-DIMENSIONAL STRUCTURE OF CALICIVIRUS
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DOI：
10.1006/jmbi.1994.1439
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发表时间：
1994-07-15
影响因子：
5.6
通讯作者：
SMITH, AW
中科院分区：
文献类型：
--
作者：
PRASAD, BVV;MATSON, DO;SMITH, AW
杯状病毒科包括一个新的单链RNA病毒家族。人类杯状病毒引起胃肠炎，而动物杯状病毒引起多种疾病。我们用电子冷冻显微镜和计算机图像处理技术确定了灵长类杯状病毒的三维结构。杯状病毒是一种罕见的动物病毒，其衣壳由单一结构蛋白组成。这种病毒的三维结构不同于任何其他动物病毒。然而，与番茄丛矮病毒和萝卜皱缩病毒等植物病毒在结构上有几个相似之处。钙离子直径为405？，呈T=3的二十面体对称性。三维结构的主要特征是在二十面体5折和3折轴处有32个深50？宽90？的大表面空洞，以及在局部和严格的2折轴处围绕这些空洞的90个独特的拱形胶囊。每个衣壳是衣壳蛋白的二聚体。尽管存在明显的差异，但三个准等效亚单位显示出共同的结构特征：上双叶结构域、中央茎结构域和下壳域。2倍相关的衣壳蛋白通过双叶结构域相互作用，形成拱顶。这三个亚基之间茎和壳结构域连接器之间的结构差异表明，存在一个铰链区，这可能有助于衣壳蛋白适应Thet=3二十面体结构的三个准等价环境。五价衣壳蛋白和六价衣壳蛋白的壳域结合在一起，形成了半径在115和150？之间的连续壳层。对于壳域，提出了一种β-Barrel结构。内壳的质量密度在85到110？之间可能包含与RNA相互作用的衣壳蛋白的一部分。在45和85？半径之间的特征暗示着有序的RNA。
The Caliciviradae comprise a new family of single-stranded RNA viruses. While human caliciviruses cause gastroenteritis, the animal caliciviruses cause a wide range of disease. We have determined the three-dimensional structure of a primate calicivirus using electron cryomicroscopy and computer image-processing techniques. Calicivirus is one of the rare animal viruses whose capsid is made of a single structural protein. The three-dimensional structure of the virus is distinct from that of any other animal virus. However, there are several architectural similarities with plant viruses such as tomato bushy stunt virus and turnip crinkle virus. The calicivirions are 405 Å in diameter and exhibitT= 3 icosahedral symmetry. The main features of the three-dimensional structure are the 32 large surface hollows, 50 Å deep and 90 Å wide, at the icosahedral 5-fold and 3 fold axes, and the 90 distinctive arch-like capsomeres surrounding these hollows at the local and strict 2-fold axes. Each capsomere is a dimer of the capsid protein. Despite noticeable differences, the three quasi-equivalent subunits show common structural features: the upper bilobed domain, the central stem domain, and the lower shell domain. The 2-fold related capsid proteins interact through the bilobed domains to form the top of the arch. The structural differences between the connectors of the stem and the shell domain among the three subunits suggest the presence of a hinge region that may facilitate the capsid protein to adapt to the three quasi-equivalent environments of theT= 3 icosahedral structure. The shell domains of the pentavalent and hexavalent capsid proteins associate to form a continuous shell between the radii of 115 and 150 Å. A β-barrel structure has been suggested for the shell domain. The mass density in the inner shell between the radius of 85 and 110 Å may contain a portion of the capsid protein interacting with the RNA. The features between the 45 and 85 Å radius are suggestive of ordered RNA.