Department of Molecular Biology, University Medical Center Göttingen, 37073, Göttingen, Germany.
Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.
Nat Commun. 2018 Dec 19;9(1):5383. doi: 10.1038/s41467-018-07783-w.
Production of eukaryotic ribosomal subunits is a highly dynamic process; pre-ribosomes undergo numerous structural rearrangements that establish the architecture present in mature complexes and serve as key checkpoints, ensuring the fidelity of ribosome assembly. Using in vivo crosslinking, we here identify the pre-ribosomal binding sites of three RNA helicases. Our data support roles for Has1 in triggering release of the U14 snoRNP, a critical event during early 40S maturation, and in driving assembly of domain I of pre-60S complexes. Binding of Mak5 to domain II of pre-60S complexes promotes recruitment of the ribosomal protein Rpl10, which is necessary for subunit joining and ribosome function. Spb4 binds to a molecular hinge at the base of ES27 facilitating binding of the export factor Arx1, thereby promoting pre-60S export competence. Our data provide important insights into the driving forces behind key structural remodelling events during ribosomal subunit assembly.
真核核糖体亚基的合成是一个高度动态的过程；前核糖体经历了许多结构重排，这些重排建立了成熟复合物中的结构，并作为关键的检查点，确保核糖体组装的保真度。使用体内交联技术，我们在这里确定了三个 RNA 解旋酶的前核糖体结合位点。我们的数据支持 Has1 在触发 U14 snoRNP 释放中的作用，这是早期 40S 成熟过程中的一个关键事件，以及在驱动 pre-60S 复合物结构域 I 组装中的作用。Mak5 与 pre-60S 复合物的结构域 II 结合，促进核糖体蛋白 Rpl10 的募集，这对于亚基连接和核糖体功能是必需的。Spb4 结合到 ES27 底部的一个分子铰链上，促进了出口因子 Arx1 的结合，从而促进 pre-60S 出口能力。我们的数据为核糖体亚基组装过程中关键结构重塑事件背后的驱动力提供了重要的见解。
