期刊
SCIENCE
卷 353, 期 6306, 页码 1399-1405出版社
AMER ASSOC ADVANCEMENT SCIENCE
DOI: 10.1126/science.aag1906
关键词
-
资金
- Deutsche Forschungsgemeinschaft [SFB 860]
The activated spliceosome (B-act) is in a catalytically inactive state and is remodeled into a catalytically active machine by the RNA helicase Prp2, but the mechanism is unclear. Here, we describe a 3D electron cryomicroscopy structure of the Saccharomyces cerevisiae B-act complex at 5.8-angstrom resolution. Our model reveals that in B-act, the catalytic U2/U6 RNA-Prp8 ribonucleoprotein core is already established, and the 5' splice site (ss) is oriented for step 1 catalysis but occluded by protein. The first-step nucleophile-the branchsite adenosine-is sequestered within the Hsh155 HEAT domain and is held 50 angstroms away from the 5' ss. Our structure suggests that Prp2 adenosine triphosphatase-mediated remodeling leads to conformational changes in Hsh155's HEAT domain that liberate the first-step reactants for catalysis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据