Structure of the no-go mRNA decay complex Dom34-Hbs1 bound to a stalled 80S ribosome
Structure of the no-go mRNA decay complex Dom34-Hbs1 bound to a stalled 80S ribosome
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DOI：
10.1038/nsmb.2057
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发表时间：
2011-06-01
影响因子：
16.8
通讯作者：
Beckmann, Roland
中科院分区：
文献类型：
--
作者：
Becker, Thomas;Armache, Jean-Paul;Beckmann, Roland
NO-GO衰变(NGD)是真核细胞中的一种mRNA质量控制机制，它导致在翻译延伸过程中停滞不前的mRNAs的降解。触发NGD的关键因素是Dom34和Hbs1。我们用冷冻EM观察了Dom34-Hbs1复合体与停滞的核糖体结合产生的NGD中间体。在亚纳米分辨率下，Dom34和Hbs1的所有结构域都被识别出来，允许晶体结构和同源模型的对接。此外，Dom34和Hbs1与真核释放因子(ERF)结构上的相似性使我们能够提出一个与核糖体结合的eRF1-eRF3复合体的模型。总体而言，我们的数据提供了对核糖体上如何识别停滞的mRNA以及ERF复合体如何同时识别终止密码子和催化肽释放的结构见解。
No-go decay (NGD) is a mRNA quality-control mechanism in eukaryotic cells that leads to degradation of mRNAs stalled during translational elongation. The key factors triggering NGD are Dom34 and Hbs1. We used cryo-EM to visualize NGD intermediates resulting from binding of the Dom34-Hbs1 complex to stalled ribosomes. At subnanometer resolution, all domains of Dom34 and Hbs1 were identified, allowing the docking of crystal structures and homology models. Moreover, the close structural similarity of Dom34 and Hbs1 to eukaryotic release factors (eRFs) enabled us to propose a model for the ribosome-bound eRF1-eRF3 complex. Collectively, our data provide structural insights into how stalled mRNA is recognized on the ribosome and how the eRF complex can simultaneously recognize stop codons and catalyze peptide release.