Unraveling the dynamics of ribosome translocation
Unraveling the dynamics of ribosome translocation
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DOI：
10.1016/j.sbi.2012.09.004
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发表时间：
2012-12-01
影响因子：
6.8
通讯作者：
Puglisi, Joseph D.
中科院分区：
文献类型：
--
作者：
Chen, Jin;Tsai, Albert;Puglisi, Joseph D.
易位是翻译中的关键事件之一，需要核糖体的大规模构象变化，两个转移RNA(TRNAs)跨越20埃以上的距离，以及信使RNA(MRNA)以一个密码子的耦合移动，完成一个肽链延长周期。反式转位是由延伸因子G(细菌中的EF-G)催化的，它在这个过程中水解GTP。然而，核糖体的构象重排如何实际驱动tRNAs的运动，以及EF-G GTP水解如何在这一过程中发挥作用仍不清楚。荧光方法，无论是单分子的还是整体的，都提供了易位的动态视图，使我们能够实时跟踪核糖体的不同构象变化。电子显微镜的应用揭示了转位过程中的新构象中间产物和驱动tRNA运动的核糖体中的重要结构重排，而计算方法则增加了对翻译途径的定量观察。这些最新进展揭示了易位的过程，为如何解决当前文献中对易位的不同描述提供了洞察力。
Translocation is one of the key events in translation, requiring large-scale conformational changes in the ribosome, movements of two transfer RNAs (tRNAs) across a distance of more than 20 angstrom, and the coupled movement of the messenger RNA (mRNA) by one codon, completing one cycle of peptide-chain elongation. Trans location is catalyzed by elongation factor G (EF-G in bacteria), which hydrolyzes GTP in the process. However, how the conformational rearrangements of the ribosome actually drive the movements of the tRNAs and how EF-G GTP hydrolysis plays a role in this process are still unclear. Fluorescence methods, both single-molecule and bulk, have provided a dynamic view of translocation, allowing us to follow the different conformational changes of the ribosome in real-time. The application of electron microscopy has revealed new conformational intermediates during translocation and important structural rearrangements in the ribosome that drive tRNA movement, while computational approaches have added quantitative views of the translational pathway. These recent advances shed light on the process of translocation, providing insight on how to resolve the different descriptions of translocation in the current literature.