Translational Quality Control by Bacterial Threonyl-tRNA Synthetases*
Translational Quality Control by Bacterial Threonyl-tRNA Synthetases*
复制标题
DOI：
10.1074/jbc.m116.740472
复制
发表时间：
2016-08
期刊：
影响因子：
--
通讯作者：
Xiao-Long Zhou;Yun Chen;Z. Fang;Zhi-Rong Ruan;Yong Wang;Ru-Juan Liu;Mei-Qin Xue;E. Wang
中科院分区：
文献类型：
--
作者：
Xiao-Long Zhou;Yun Chen;Z. Fang;Zhi-Rong Ruan;Yong Wang;Ru-Juan Liu;Mei-Qin Xue;E. Wang
由氨酰-tRNA合成酶介导的翻译保真度确保了正确的氨酰-tRNA的产生，这对大多数物种至关重要。苏氨酰-tRNA合成酶（ThrRS）含有多个结构域，包括N2编辑结构域。在ThrRS域中，N1是最后被分配功能的域。在这里，我们发现，从支原体物种的ThrRS表现出不同的结构域组成和编辑活性位点相比，典型的ThrRS。支原体移动的ThrRS是天然缺乏N1结构域的ThrRS的第一个例子，显示出有效的转移后编辑活性。与此相反，山羊支原体ThrRS，其中含有一个N1结构域和一个简并的N2结构域，是编辑缺陷。只有具有编辑能力的ThrRS能够支持酵母thrS缺失菌株（ScΔthrS）的生长，因此表明ScΔthrS是研究引入的细菌ThrRS的体内编辑的极好工具。基于N1结构域的存在与否，我们进一步揭示了N1结构域中唯一绝对保守的残基在大肠杆菌ThrRS中通过介导N1-N2结构域相互作用调节编辑中的至关重要性。我们的研究结果揭示了各种ThrRS的翻译质量控制和N1结构域在翻译保真度中的作用。
Translational fidelity mediated by aminoacyl-tRNA synthetases ensures the generation of the correct aminoacyl-tRNAs, which is critical for most species. Threonyl-tRNA synthetase (ThrRS) contains multiple domains, including an N2 editing domain. Of the ThrRS domains, N1 is the last to be assigned a function. Here, we found that ThrRSs from Mycoplasma species exhibit differences in their domain composition and editing active sites compared with the canonical ThrRSs. The Mycoplasma mobile ThrRS, the first example of a ThrRS naturally lacking the N1 domain, displays efficient post-transfer editing activity. In contrast, the Mycoplasma capricolum ThrRS, which harbors an N1 domain and a degenerate N2 domain, is editing-defective. Only editing-capable ThrRSs were able to support the growth of a yeast thrS deletion strain (ScΔthrS), thus suggesting that ScΔthrS is an excellent tool for studying the in vivo editing of introduced bacterial ThrRSs. On the basis of the presence or absence of an N1 domain, we further revealed the crucial importance of the only absolutely conserved residue within the N1 domain in regulating editing by mediating an N1-N2 domain interaction in Escherichia coli ThrRS. Our results reveal the translational quality control of various ThrRSs and the role of the N1 domain in translational fidelity.