DOES THE GENOME DETERMINE THE SIZE OF A VIRUS? - STUDYING VIRAL RNA IN SOLUTIONS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。这项建议概述了我们使用小角x射线散射方法研究病毒RNA的必要性。特别是，我们专注于相对较好的植物病毒(CCMV和BMV)，并概述了SAXS实验，这些实验将有助于阐明控制病毒衣壳内基因组物质(本例中为RNA)的自组装和组织的力。通过比较溶液中病毒RNA的形状和大小，以及相同长度的各种非病毒(如信使、核糖体和随机)RNA的形状和大小，我们希望验证第一种情况下的二级/三级结构是否与其他情况下的有根本不同。此外，我们希望确定这些生物聚合物对离子环境变化的敏感度。具体地说，在生理盐分条件下，构象的变化是否与蛋白质衣壳呈现的内部体积限制相关。我们希望这些研究最终将引导我们回答更微妙的问题，例如：a)病毒RNA中的核苷酸序列是否明确编码有利于包装的特殊二级和三级结构，以及b)对于给定的衣壳蛋白，RNA的序列和长度是否因此控制了组装颗粒的首选大小(T数)。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This proposal outlines our need for studying viral RNA using small-angle x-ray scattering methods. In particular we focus on relatively well characterized plant viruses (CCMV and BMV), and outline SAXS experiments that would help elucidate the forces governing self-assembly and organization of genomic material (RNA in this case) inside the viral capsid. By comparing the shape and size of the viral RNA in solution with those of various non-viral (e.g., messenger, ribosomal and random) RNAs of the same length, we hope to verify if the secondary/tertiary structure in the first case is fundamentally different from that of the others. Further, we would like to determine how sensitive these biopolymers are to changes in ionic environment. Specifically, under physiological salt conditions, do the changes in conformation correlate with the internal volume restrictions presented by a protein capsid. We hope these studies will eventually lead us towards answering more subtle questions such as: a) does the sequence of nucleotides in viral RNA explicitly code for a special secondary and tertiary structure conducive to packaging, and b) for a given capsid protein, do the sequence and length of RNA therefore control the preferred size (T-number) of the assembled particle over others.