人类17S U2 snRNP的分子结构
Zhenwei Zhang1, Cindy L Will2, Karl Bertram1
1Department of Structural Dynamics, MPI for Biophysical Chemistry, Göttingen, Germany.
Nature
|June 5, 2020
概括
U2小核核蛋白 (snRNP) 结构揭示了SF3B1如何保持开放的构造,与PRP5和TAT-SF1相互作用. 这解释了在拼接过程中形成稳定的U2 snRNA分支的必要重新排列.
科学领域:
- 分子生物学
- 结构生物学
- 进行RNA处理
背景情况:
- 通过选择分支部位腺素,U2小核核蛋白 (snRNP) 对于前体mRNA拼接至关重要.
- 稳定的U2 snRNP添加到结合体需要DEAD-box ATPase PRP5.
- 人类U2 snRNA的折叠和分支点相互作用的干环 (BSL) 形成以及SF3B1的作用仍然不完全理解.
研究的目的:
- 确定人类17S U2 snRNP的分子结构.
- 阐明U2 snRNP-分支站点相互作用的结构基础.
- 了解SF3B1,PRP5和TAT-SF1在U2 snRNP组装和功能中的作用.
主要方法:
- 人类17S U2 snRNP的3D冷电子显微镜.
- 蛋白质交联数据分析.
- 整合结构和生化数据以确定分子结构.
主要成果:
- 3D冷-EM结构显示SF3B1与PRP5和TAT-SF1相互作用,在U2 snRNP中保持开放的构造.
- 人类U2 snRNA形成了一个BSL结构,位于PRP5,TAT-SF1和SF3B1之间.
- 稳定的U2分支位螺旋形成需要BSL的大量重塑和相互作用蛋白的位移.
结论:
- 这项研究提供了对稳定添加U2到结合体所需的TAT-SF1位移的结构解释.
- 通过PRP5进行的确定RNP重组对于稳定的U2分支站互动至关重要.
- 这些发现澄清了早期结合酶组合和U2 snRNP功能的结构机制.
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