在核和细胞质状态下tRNA出口因子的结构
Atlanta G Cook1, Noemi Fukuhara, Martin Jinek
1Structural Cell Biology, MPI for Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Nature
|August 15, 2009
概括
糖蛋白-β因子Xpot结合转移RNA (tRNA) 并调解它们从核输出至细胞质. 结构分析显示Xpot包裹在tRNA周围,确保正确的处理和质量控制.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 结构生物学 结构生物学
背景情况:
- 转移RNA (tRNA) 是蛋白质合成的必需分子,在核糖体上解码信使RNA (mRNA).
- 在真核生物中,tRNAs是在核中合成的,必须被运送到细胞质中才能发挥作用.
- 这种核细胞质运输是由特定的蛋白质因素促进的.
研究的目的:
- 为了阐明tRNA核细胞质出口的结构机制.
- 了解运输因子Xpot如何识别并与tRNA结合.
- 调查Xpot在将tRNA出口与质量控制相结合方面的作用.
主要方法:
- 使用X射线晶体学来确定Schizosaccharomyces pombe Xpot. 的结构.
- 解决了与tRNA和RanGTP复合的未结合的Xpot和Xpot的结构.
- 实现的分辨率为未结合的Xpot的3.1 Å,复合的3.2 Å.
主要成果:
- 该研究确定了Xpot的高分辨率结构,提供了其核和细胞质状态的快照.
- 在结合tRNA时,Xpot经历了显著的形状变化,绕着分子.
- 结合主要涉及tRNA的5'和3'末端,解释了识别特异性.
结论:
- 克斯波特的结构揭示了它识别成熟tRNA的机制.
- 结合模式解释了Xpot如何区分处理和未处理的tRNA.
- 这种机制确保只有正确处理的tRNA才能从核中出口,将出口与质量控制联系起来.
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