中国科学院生物物理研究所叶克穷课题组解析出过渡状态下90S小核糖体亚基前体的冷冻电镜结构。相关论文于2020年9月18日发表于国际学术期刊《科学》。

Title: Cryo-EM structure of 90S small ribosomal subunit precursors in transition states

Author: Yifei Du, Weidong An, Xing Zhu, Qi Sun, Jia Qi, Keqiong Ye

Issue&Volume: 2020/09/18

Abstract: The 90S preribosome is a large, early assembly intermediate of small ribosomal subunits that undergoes structural changes to give a pre-40S ribosome. Here, we gained insight into this transition by determining cryo–electron microscopy structures of Saccharomyces cerevisiae intermediates in the path from the 90S to the pre-40S. The full transition is blocked by deletion of RNA helicase Dhr1. A series of structural snapshots revealed that the excised 5′ external transcribed spacer (5′ ETS) is degraded within 90S, driving stepwise disassembly of assembly factors and ribosome maturation. The nuclear exosome, an RNA degradation machine, docks on the 90S through helicase Mtr4 and is primed to digest the 3′ end of the 5′ ETS. The structures resolved between 3.2- and 8.6-angstrom resolution reveal key intermediates and the critical role of 5′ ETS degradation in 90S progression.

DOI: 10.1126/science.aba9690

Source: https://science.sciencemag.org/content/369/6510/1477