Analysis of assembly mechanism of spherical virus based on its high resolution three-dimensional structure

基于高分辨率三维结构的球形病毒组装机制分析

• 批准号: 10680634
• 负责人: FUKUYAMA Keiichi
• 金额: $ 2.24万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680634/
• 关键词: tobacco necrosis virus; x-ray crystallographic analysis; three dimensioual structure of virus; protein-protein interactiou; assembly mechauism; ウイルスの立体構造

Tobacco necrosis virus (TNV) is a spherical virus that contains ss-RNA (1.3x10ィイD16ィエD1 Da) as a genome. TNV causes such plants as C. quinoa and tulip necrotic lesions. TNV coat protein has 276 amino acid residues; the amino acid sequence was determined by a combination of peptide and DNA sequencing. 180 copies of the protein assemble to form T=3 icosahedral shell. Thus, the virus shell has three stereochemically independent subunits (A, B and C) with identical primary structure.TNV crystallized in space group P4ィイD22ィエD232, with a=336.4Å. Unit cell contains two TNV particles. Diffraction data of TNV crystals were collected to 2.25Å resolution using synchotron radiation and Weissenberg camera for macromolecules at BL6A, Photon Factory, Tsukuba. The structure was solved by averaging the electron density of non-crystallographic units and refined by XPLOR to R=25.3%.The subunits have a fold of jelly roll β-barrel. Respective N-terminal 86, 87 and 56 residues of A,B and C subunits are disordered. The segment ordered only in C subunit (arm) produces diversity of the subunit interactions; A subunits form pentermers at five-fold axis, whereas B and C subunits form hexamers at icosahedral three-fold axis, where three arms of C-subunits form a β-annulus. Five calcium ion per icosahedral asymmetric unit were identified. These are located at the subunit interfaces.

烟草坏死病毒（TNV）是一种球形病毒，包含SS-RNA（1.3x10d16ed1 DA）作为基因组。 TNV引起诸如藜麦和郁金香坏死病变等植物。 TNV涂层蛋白具有276个氨基酸残基；通过肽和DNA测序的组合确定氨基酸序列。 180份蛋白质组装以形成t = 3二十面体壳。这就是病毒壳具有三个立体化学独立的亚基（A，B和C），具有相同的主要结构。TNV在空间组P4D22E D232中结晶，A =336.4Å。单元电池包含两个TNV颗粒。使用Synchotron辐射和Weissenberg摄像机在Tsukuba Photon Factory的大分子中，将TNV晶体的衍射数据收集到2.25Å分辨率。通过平均非结晶单元的电子密度来求解结构，并通过Xplor精制到r = 25.3％。亚基具有果冻滚动β-桶的折叠。 A，B和C亚基的各个N末端86、87和56的结果是无序的。仅在C子单元（ARM）中排序的细分市场产生亚基相互作用的多样性。一个亚基在五倍的轴上形成了驾驶员，而B和C亚基在二十面体的三个轴上形成六聚体，其中三个c-Subunit的臂形成Aβ-Annulus。每个二十面体不对称单位五个钙离子。这些位于亚基接口。