CryoEM structure of yeast cytoplasmic exosome complex  

酵母的 CryoEM 结构细胞质的 exosome 建筑群

作　　者：Jun-Jie Liu Chu-Ya Niu Yao Wu Dan Tan Yang Wang Ming-Da Ye Yang Liu Wenwei Zhao Ke Zhou Quan-Sheng Liu Junbiao Dai Xuerui Yang Meng-Qiu Dong Niu Huang Hong-Wei Wang 

机构地区：[1]Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China [2]Joint Graduate Program of Peking-Tsinghua-National Institute of Biological Science, Tsinghua University, Beijing 100084, China [3]National In- stitute of Biological Sciences, Beijing 102206, China [4]MOE Key Laboratory of Bioinformatics, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China [5]The Multidiscipline Research Center, Institute of High Energy Physics of the Chinese Academy of Sciences, Beijing 100049, China [6]MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China

出　　处：《Cell Research》2016年第7期822-837,共16页细胞研究（英文版）

摘　　要：The eukaryotic multi-subunit RNA exosome complex plays crucial roles in 3＇-to-5＇ RNA processing and decay. Rrp6 and Ski7 are the major cofactors for the nuclear and cytoplasmic exosomes, respectively. In the cytoplasm, Ski7 helps the exosome to target mRNAs for degradation and turnover via a through-core pathway. However, the interaction between Ski7 and the exosome complex has remained unclear. The transaction of RNA substrates within the exosome is also elusive. In this work, we used single-particle cryo-electron microscopy to solve the structures of the Ski7-exosome complex in RNA-free and RNA-bound forms at resolutions of 4.2 A and 5.8A, respectively. These structures reveal that the N-terminal domain of Ski7 adopts a structural arrangement and interacts with the exosome in a similar fashion to the C-terminal domain of nuclear Rrp6. Further structural analysis of exosomes with RNA substrates harboring 3＇ overhangs of different length suggests a switch mechanism of RNA-induced exosome activa- tion in the through-core pathway of RNA processing.

关 键 词：EXOSOME RNA decay Ski7 Rrp6 CRYO-EM 

分 类 号：Q945.11[生物学—植物学] Q51