Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA.
Arch Virol. 2013 Aug;158(8):1661-9. doi: 10.1007/s00705-013-1650-6. Epub 2013 Mar 13.
Red clover necrotic mosaic virus (RCNMV) is a 36-nm-diameter, T = 3 icosahedral plant virus with a genome that is split between two single-stranded RNA molecules of approximately 3.9 kb and 1.5 kb, as well as a 400-nucleotide degradation product. The structure of the virus capsid and its response to removing Ca(2+) and Mg(2+) was previously studied by cryo-electron microscopy (cryo-EM) (Sherman et al. J Virol 80:10395-10406, 2006) but the structure of the RNA was only partially resolved in that study. To better understand the organization of the RNA and conformational changes resulting from the removal of divalent cations, small-angle neutron scattering with contrast variation experiments were performed. The results expand upon the cryo-EM results by clearly showing that virtually all of the RNA is contained in a thin shell that is in contact with the interior domains of the viral capsid protein, and they provide new insight into changes in the RNA packing that result from removal of divalent cations.
红车轴草坏死花叶病毒（RCNMV）是一种直径为 36nm 的 T=3 二十面体植物病毒，其基因组分为两个单链 RNA 分子，大小约为 3.9kb 和 1.5kb，以及一个 400 个核苷酸的降解产物。该病毒衣壳的结构及其对去除 Ca（2+）和 Mg（2+）的反应先前已通过冷冻电镜（cryo-EM）进行了研究（Sherman 等人，J Virol 80:10395-10406，2006），但在该研究中仅部分解析了 RNA 的结构。为了更好地了解 RNA 的组织和由于去除二价阳离子而导致的构象变化，进行了带有对比度变化实验的小角中子散射实验。结果通过清楚地表明几乎所有的 RNA 都包含在与病毒衣壳蛋白的内部结构域接触的薄壳中，从而扩展了 cryo-EM 的结果，并为由于去除二价阳离子而导致的 RNA 包装的变化提供了新的见解。
