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在核糖体形成过程中协调5S RNP旋转与ITS2前RNA处理的结构洞察

Matthias Thoms¹, Benjamin Lau², Jingdong Cheng³

¹Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany.

|November 3, 2023

概括

对于核糖体生物发生和基因沉默至关重要的核糖体,在Chaetomium thermophilum中具有保存的结构. 它的两个模块协调rRNA处理和ITS2的去除,帮助核糖体成熟.

科学领域:

分子生物学分子生物学
结构生物学结构生物学
生物化学生物化学

背景情况:

核糖体是参与核糖体生物发生和真核生物中的基因沉默的关键复合体.
以前的研究已经确定了它在酵母和人类系统中的作用.

研究的目的:

从热友菌Chaetomium thermophilum中分离和结构性地表征保存的瑞克索组.
阐明体协调前核糖体RNA处理和核糖体成熟的分子机制.

主要方法:

电子显微镜 (Cryo-EM) 或X射线晶体学以确定体的结构.
生物化学试验用于研究基因组子模块 (Las1内核酶,Grc3多核酸酶) 的酶活性.
试验室内复制试验证明了在rRNA前处理过程中瑞克索组模块的功能协调.

主要成果:

来自C. thermophilum的瑞克索组由两个不同的子模块组成:Rix1-Ipi3-Ipi1复合体和Las1-Grc3复合体,灵活连接.
里克斯1复合体将5SrRNA定位在60S前颗粒上进行适当的折叠和成熟.
Las1-Grc3模块分裂和5'化了前rRNA的内部转录间隔器2 (ITS2) 区域,促进其通过Mtr4酶-外基因组通路去除.

结论:

确定的结构揭示了不同基因组模块之间的复杂协调,促进了核糖体生物发生的关键步骤.
这些发现提供了机理性的洞察力,了解体如何协调rRNA处理事件,包括ITS2删除.
瑞克索姆的保存性表明,类似的结构和功能策略可能被用于基因沉默通路.

关键词:

在 5S RNP 中,有 5S RNP.这就是ITS2的意义.在 pre-60S 核糖体前核糖体生物发生的生物.一个Rixosome的存在.

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