Structures of tmRNA and SmpB as they transit through the ribosome.
Structures of tmRNA and SmpB as they transit through the ribosome.
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DOI：
10.1038/s41467-021-24881-4
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发表时间：
2021-08-13
影响因子：
16.6
通讯作者：
Gillet R
中科院分区：
文献类型：
--
作者：
Guyomar C;D'Urso G;Chat S;Giudice E;Gillet R
在细菌中，反翻译是主要的拯救系统，释放在有缺陷的信使rna上停滞的核糖体。这种机制是由小蛋白B （SmpB）和传递信使RNA （tmRNA）驱动的，tmRNA是一种已知具有trna样结构域和mrna样结构域的杂交RNA。在这里，我们展示了四个核糖体在反译过程中的低温电镜结构，分辨率从3.0到3.4 Å。这些包括整个预调节状态的高分辨率结构，以及调节状态、易位状态和易位中间体的结构。他们共同阐明了核糖体中tmRNA-SmpB复合物的运动，从其由延伸因子EF-Tu传递到B1桥打开后通过核糖体A和P位点。此外，我们还描述了tmRNA-SmpB复合物与核糖体之间的相互作用。这些解释了为什么这个过程不会干扰正典翻译。在细菌中，由小蛋白B （SmpB）和传递信使RNA （tmRNA）介导的反式翻译使停滞在缺陷mrna上的核糖体能够再循环。在这里，作者报告了核糖体在反翻译过程中的结构，揭示了一个易位中间体，并阐明了核糖体中tmRNA-SmpB复合物的运动。
In bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), a hybrid RNA known to have both a tRNA-like and an mRNA-like domain. Here we present four cryo-EM structures of the ribosome during trans-translation at resolutions from 3.0 to 3.4 Å. These include the high-resolution structure of the whole pre-accommodated state, as well as structures of the accommodated state, the translocated state, and a translocation intermediate. Together, they shed light on the movements of the tmRNA-SmpB complex in the ribosome, from its delivery by the elongation factor EF-Tu to its passage through the ribosomal A and P sites after the opening of the B1 bridges. Additionally, we describe the interactions between the tmRNA-SmpB complex and the ribosome. These explain why the process does not interfere with canonical translation. Trans-translation, mediated by small protein B (SmpB) and transfer-messenger RNA (tmRNA), enables recycling of the ribosomes stalled on defective mRNAs in bacteria. Here, the authors report structures of the ribosome during trans-translation that reveal a translocation intermediate and elucidate the movements of the tmRNA-SmpB complex in the ribosome.
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DOI：
10.1107/s2059798318009324
发表时间：
2018-09-01
期刊：
Acta crystallographica. Section D, Structural biology
影响因子：
--
作者：
Afonine PV;Klaholz BP;Moriarty NW;Poon BK;Sobolev OV;Terwilliger TC;Adams PD;Urzhumtsev A
通讯作者：
Urzhumtsev A
影响因子：
7.7
作者：
Bai, Xiao-chen;Rajendra, Eeson;Scheres, Sjors H. W.
通讯作者：
Scheres, Sjors H. W.
影响因子：
14.9
作者：
Hanawa-Suetsugu, K;Takagi, M;Muto, A
通讯作者：
Muto, A
影响因子：
14.9
作者：
Guyomar, Charlotte;Thepaut, Marion;Gillet, Reynald
通讯作者：
Gillet, Reynald
影响因子：
16.6
作者：
Carbone CE;Demo G;Madireddy R;Svidritskiy E;Korostelev AA
通讯作者：
Korostelev AA