Molecular architecture of the 90S small subunit pre-ribosome
Molecular architecture of the 90S small subunit pre-ribosome
复制标题
90S小亚基前核糖体的分子结构
DOI：
10.7554/elife.22086
复制
发表时间：
2017-02-28
期刊：
影响因子：
7.7
通讯作者：
Ye, Keqiong
中科院分区：
文献类型：
--
作者：
Sun, Qi;Zhu, Xing;Ye, Keqiong
真核小核糖体亚基首先组装成90S前核糖体。完整的90 S是一个巨大的复合体，分子量约为5兆道尔顿。在这里，我们报告了几乎完整的架构酿酒酵母90S确定从三个冷冻电子显微镜单颗粒重建在4.5至8.7埃的分辨率。对大多数密度图进行建模，并将其分配给特定的RNA和蛋白质组分。新生的核糖体被组装成孤立的天然样亚结构，这些亚结构由丰富的组装因子稳定。5'外转录间隔区和U3 snoRNA使支撑新生核糖体的大亚复合物成核。U3结合前rRNA的四个位点，包括螺旋27上的新位点，但不结合中央假结的3'侧，并且关键地组织90S结构。90S模型为小亚基组装的原理和组装因子的功能提供了重要的见解。DOI：http://dx.doi.org/10.7554/eLife.22086.001网站
Eukaryotic small ribosomal subunits are first assembled into 90S pre-ribosomes. The complete 90S is a gigantic complex with a molecular mass of approximately five megadaltons. Here, we report the nearly complete architecture of Saccharomyces cerevisiae 90S determined from three cryo-electron microscopy single particle reconstructions at 4.5 to 8.7 angstrom resolution. The majority of the density maps were modeled and assigned to specific RNA and protein components. The nascent ribosome is assembled into isolated native-like substructures that are stabilized by abundant assembly factors. The 5' external transcribed spacer and U3 snoRNA nucleate a large subcomplex that scaffolds the nascent ribosome. U3 binds four sites of pre-rRNA, including a novel site on helix 27 but not the 3' side of the central pseudoknot, and crucially organizes the 90S structure. The 90S model provides significant insight into the principle of small subunit assembly and the function of assembly factors. DOI: http://dx.doi.org/10.7554/eLife.22086.001