一个Lsm11的N端螺旋稳定了CPSF73在U7的snRNP中,用于组织蛋白前mRNA3'-end处理
Anthony Desotell1, William F Marzluff2,3, Zbigniew Dominski2,3
1Department of Biological Sciences, Columbia University, New York, NY 10027, United States.
Nucleic acids research
|January 7, 2026
概括
Lsm11螺旋对U7 snRNP功能在基因素前mRNA处理中至关重要. 结构研究揭示了CPSF73
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 处理RNA处理RNA处理
背景情况:
- U7小核核核糖核蛋白 (snRNP) 综合体对于复制依赖的素前mRNAs的3'-end处理至关重要.
- 这种处理是由U7 snRNP内核酶,CPSF73.3进行的.
研究的目的:
- 研究Lsm11 N端延伸中螺旋体对U7 snRNP活动的结构和功能重要性.
- 为了阐明CPSF73在裂变反应期间的形状灵活性.
- 为了确定U7 snRNP复合体内的新型蛋白相互作用.
主要方法:
- 在Lsm11 N-终端螺旋体的位点定向突变发生.
- 低温电子显微镜 (cryo-EM) 用于确定结构细节.
- 在体外复制U7 snRNP复合物.
主要成果:
- Lsm11螺旋中的突变或缺失显著降低了mRNA分离前活性.
- 低温电磁探测显示,螺旋对于在裂变过程中定位CPSF73至关重要.
- CPSF73可以采用一种开放的,独立于直接与其活性位点结合的RNA的活性构造.
- 保存的C端螺旋CstF77与CPSF100结合,对裂解活动的影响很小.
结论:
- 保存的Lsm11 N端螺旋对U7 snRNP介导的前mRNA处理至关重要.
- 结构洞察力表明CPSF73能够在没有立即参与RNA的情况下实现活性构造.
- 在U7 snRNP复合体内的CPSF100上发现了一个新的CstF77结合位点.
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