STRUCTURE OF VIRAL RNA AND ITS ROLE IN ASSEMBLY

各种物理和化学技术，其中主要是 X射线结晶学，将应用于一系列T=1和T=3 二十面体病毒，其最终目标是(1)推导出 病毒内RNA基因组的详细结构，(2) 确定重要的蛋白质-核酸相互作用，以及(3) 为病毒粒子的组装和分解设计一个模型 与现有的生化和分子生物学数据一致。这个 待研究的病毒为卫星烟草花叶病毒(STMV)， 卫星花叶病毒(SPMV)、萝卜黄花叶病毒 (TYMV)、山豆黄斑驳病毒(DYMV)、番茄无精症病毒(TYMV) (TAV)、雀麦花叶病毒(BMV)和空衣壳 最后四个物种。这六种球形病毒代表的病毒 最广为人知的结构是病毒粒子中可见的RNA结构，以及 其中存在着最大量的数据和观测。核心RNA 通过对完整病毒的蛋白酶消化，可以制备出颗粒 并用准弹性光散射监测它们的展开。空的 衣壳可以通过冷冻解冻制成，并用于差分傅里叶变换 揭示RNA结构的合成。随着化学和化学的结合 来自计算机模拟的酶探针信息和预测 对结构和功能的全面理解将会出现。这 研究意义重大，因为核酸的构象 目前还不知道球状病毒的成分，而且有 目前还没有全面的结构基础来研究病毒的过程 装配和拆卸。

A variety of physical and chemical techniques, chief among them being X-ray crystallography, will be applied to a series of T = 1 and T = 3 icosahedral viruses with the ultimate objectives of (1) deducing the detailed structure of the RNA genomes inside the viruses, (2) identifying important protein - nucleic acid interactions, and (3) devising a model for the assembly and disassembly of the virions consistent with existing biochemical and molecular biological data. The viruses to be studied are satellite tobacco mosaic virus (STMV), satellite panicum mosaic virus (SPMV), turnip yellow mosaic virus (TYMV), Desmodium Yellow Mottle Virus (DYMV), Tomato Aspermy Virus (TAV), Bromegrass Mosaic Virus (BMV), and empty capsids of each of the last four species. These six spherical viruses represent viruses whose structures are best known, for which RNA is visible in the virion, and for which the greatest amount of data and observations exist. Core RNA particles can be prepared by protease digestion of the intact viruses and their unfolding monitored by quasi elastic light scattering. Empty capsids can be made by freeze thawing and used in difference Fourier syntheses to reveal RNA structure. With the integration of chemical and enzymatic probe information and predictions from computer modeling a comprehensive understanding of structure and function will emerge. This research is significant because the conformation of the nucleic acid component of no spherical virus is currently known, and there is presently no comprehensive structural basis for the processes of viral assembly and disassembly.