The 5΄ UTR of the type I toxin ZorO can both inhibit and enhance translation.
The 5΄ UTR of the type I toxin ZorO can both inhibit and enhance translation.
复制标题
I 型毒素 ZorO 的 5α UTR 既可以抑制又可以增强翻译。
DOI：
10.1093/nar/gkw1172
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发表时间：
2017
影响因子：
14.9
通讯作者：
Fozo,ElizabethM
中科院分区：
文献类型：
--
作者：
Wen,Jia;Harp,JohnR;Fozo,ElizabethM
许多细菌I型毒素mrna具有一个长5΄未翻译区（UTR），作为相应抗毒素sRNA的靶位点。这是zoro - orzotype I系统的情况，其中OrzO抗毒素碱基与174个核苷酸的zoro5 ΄ UTR配对。在这里，我们证明了zorotype I毒素的全长5΄ UTR阻碍其独立于sRNA的翻译，而经过处理的5΄ UTR （zorOΔ28）促进翻译。全长zoro5 UTR折叠成广泛的二级结构，隔离核糖体结合位点（RBS）。5 - UTR的处理不会改变RBS结构，但会在RBS上游打开一个大区域（EAP区域）。截断EAP区域会损害翻译功能，但暴露RBS后可以修复这一缺陷。此外，zoro的最佳翻译需要跨越+35到+50的zoromrna区域。重要的是，5΄ UTR对翻译的积极和消极影响可以转移到报告基因上，这表明5΄ UTR可以单独驱动调控。此外，我们发现OrzO sRNA可以通过与EAP区域的碱基配对来抑制zoro翻译。
Many bacterial type I toxin mRNAs possess a long 5΄ untranslated region (UTR) that serves as the target site of the corresponding antitoxin sRNA. This is the case for thezorO-orzOtype I system where the OrzO antitoxin base pairs to the 174-nucleotidezorO5΄ UTR. Here, we demonstrate that the full-length 5΄ UTR of thezorOtype I toxin hinders its own translation independent of the sRNA whereas a processed 5΄ UTR (zorOΔ28) promotes translation. The full-lengthzorO5΄ UTR folds into an extensive secondary structure sequestering the ribosome binding site (RBS). Processing of the 5΄ UTR does not alter the RBS structure, but opens a large region (EAP region) located upstream of the RBS. Truncation of this EAP region impairszorOtranslation, but this defect can be rescued upon exposing the RBS. Additionally, the region spanning +35 to +50 of thezorOmRNA is needed for optimal translation ofzorO. Importantly, the positive and negative effects on translation imparted by the 5΄ UTR can be transferred onto a reporter gene, indicative that the 5΄ UTR can solely drive regulation. Moreover, we show that the OrzO sRNA can inhibitzorOtranslation via base pairing to the of the EAP region.