The refined crystal structure of cowpea mosaic virus at 2.8 Å resolution
The refined crystal structure of cowpea mosaic virus at 2.8 Å resolution
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DOI：
10.1006/viro.1999.0038
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发表时间：
1999-12-05
期刊：
影响因子：
3.7
通讯作者：
Johnson, JE
中科院分区：
文献类型：
--
作者：
Lin, TW;Chen, ZG;Johnson, JE
豇豆花叶病毒属是小核糖核酸病毒超家族中的一组植物病毒。豇豆花叶病毒属的模式成员——豇豆花叶病毒（CPMV），在立方晶系空间群I23（a = 317埃）以及六方晶系空间群P6(1)22（a = 451埃，c = 1038埃）中结晶。以立方形式确定了三种极为相似的核蛋白颗粒的结构。大约300埃的衣壳与小核糖核酸病毒衣壳相似，呈现出一种假T = 3（P = 3）的表面晶格。三个β - 三明治结构域采取两种取向，一种是长轴呈放射状，另外两种相对于衣壳球体的长轴是切向的。T = 3病毒呈现出这两种取向中的一种。CPMV衣壳可渗透铯离子，导致在一种通道状结构内部的β - 环结构紊乱，这表明存在一个离子通道。尽管单位晶胞较大，但六方晶型仍能使X射线衍射至3埃分辨率。晶格中较大的（约200埃）溶剂通道允许CPMV同源的Fab片段进行交换。作为确定CPMV/Fab复合物结构的第一步，通过用在立方晶胞中确定的CPMV模型进行分子置换，解析了P6(1)22晶体结构。（C）1999年学术出版社。
Comoviruses are a group of plant viruses in the picornavirus superfamily. The type member of comoviruses, cowpea mosaic virus (CPMV), was crystallized in the cubic space group 123, a = 317 Angstrom and the hexagonal space group P6(1)22, a = 451 Angstrom, c = 1038 Angstrom. Structures of three closely similar nucleoprotein particles were determined in the cubic form. The roughly 300-Angstrom capsid was similar to the picornavirus capsid displaying a pseudo T = 3 (P = 3) surface lattice. The three beta-sandwich domains adopt two orientations, one with the long axis radial and the other two with the long axes tangential in reference to the capsid sphere. T = 3 viruses display one or the other of these two orientations. The CPMV capsid was permeable to cesium ions, leading to a disturbance of the beta-annulus inside a channel-like structure, suggesting an ion channel. The hexagonal crystal form diffracted X rays to 3 Angstrom resolution, despite the large unit cell. The large (similar to 200 Angstrom) solvent channels in the lattice allow exchange of CPMV cognate Fab fragments. As an initial step in the structure determination of the CPMV/Fab complex, the P6(1)22 crystal structure was solved by molecular replacement with the CPMV model determined in the cubic cell. (C) 1999 Academic Press.