核糖体RNA是地球生物中最重要的非编码RNA，它和大量核糖体蛋白质组装形成核糖体，催化蛋白质的合成。在真核生物中，核糖体大小两个亚基的组装是个保守、高度复杂、动态的过程。在核糖体的体内组装过程中，有大量组装因子和核糖体亚基暂时结合，形成了一系列复杂的核糖体前体复合物。这些核糖体前体介导核糖体RNA修饰、折叠和加工、核糖体蛋白质的组装、以及核糖体的出核运输。本项目主要利用先进的冷冻电镜单颗粒重构技术,并综合其他手段获得的结构信息，解析在酵母核糖体小亚基组装过程中形成的多个核糖体前体结构，揭示小亚基组装的分子过程。

The ribosomal RNA (rRNA) is the most important non-coding RNA in organisms on earth. It associates with a large number of ribosomal proteins to form the ribosome and catalyzes protein synthesis. In eukaryotes, the assembly of small and large ribosome subunits is a conserved, highly complicated and dynamic process. Numerous assembly factors associate temporarily with the ribosome, forming a series of large pre-ribosomal particles. These pre-ribosomal particles mediate the modification, folding and processing of rRNA, assembly of ribosomal proteins and nuclear exportation. This project aims to determine the structure of several small subunit pre-ribosomes by using the advanced electron cryo-microscopy single-particle reconstruction technique and addtional structural information obtained by other methods. Our study is going to provide major insight into the molecular mechanism governing the small subunit assembly.