研究人员表示，在人类大核糖体亚单位（60S）生物生成的早期阶段，一个组装因子的集合体通过一个未知的机制建立并微调pre-60S颗粒的基本RNA功能中心。
研究人员报告了一系列人类核仁和核内pre-60S组装中间物的冷冻电子显微镜结构，分辨率为2.5到3.2埃。这些结构显示了蛋白质相互作用枢纽如何将组装因子复合物拴在核仁颗粒上，以及鸟苷三磷酸酶和腺苷三磷酸酶如何将不可逆的核苷酸水解步骤与功能中心的安装联系起来。核内阶段突出了一个保守的RNA处理复合物，即rixosome，如何将大规模的RNA构象变化与RNA降解机制的前核糖体RNA处理相联系。这些人类pre-60S颗粒的组合提供了一个丰富的基础，可用它来阐明核糖体形成的分子原理。
附：英文原文
Title: Principles of human pre-60S biogenesis
Author: Arnaud Vanden Broeck, Sebastian Klinge
Issue&Volume: 2023-07-07
Abstract: During the early stages of human large ribosomal subunit (60S) biogenesis, an ensemble of assembly factors establishes and fine-tunes the essential RNA functional centers of pre-60S particles by an unknown mechanism. Here, we report a series of cryo–electron microscopy structures of human nucleolar and nuclear pre-60S assembly intermediates at resolutions of 2.5 to 3.2 angstroms. These structures show how protein interaction hubs tether assembly factor complexes to nucleolar particles and how guanosine triphosphatases and adenosine triphosphatase couple irreversible nucleotide hydrolysis steps to the installation of functional centers. Nuclear stages highlight how a conserved RNA-processing complex, the rixosome, couples large-scale RNA conformational changes with pre–ribosomal RNA processing by the RNA degradation machinery. Our ensemble of human pre-60S particles provides a rich foundation with which to elucidate the molecular principles of ribosome formation.
DOI: adh3892
Source: https://www.science.org/doi/10.1126/science.adh3892