工程启动tRNAs可以有效地在非AUG启动码头开始翻译,并为mRNA显示多样化N终端氨基酸
Christina Helmling1, Alix I Chan1, Christian N Cunningham1
1Department of Peptide Therapeutics, Genentech, South San Francisco, CA 94080, USA.
Nucleic acids research
|January 20, 2025
概括
这项研究探讨了使用修改的启动器tRNAs (tRNAini) 来扩展mRNA显示的遗传密码. 研究人员发现tRNA折叠影响翻译启动,但工程可以恢复库生成的功能.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 合成生物学 合成生物学
背景情况:
- mRNA显示对于识别难以达到蛋白质标的高亲和度结合剂至关重要.
- 为成功的mRNA显示选择,生成具有数万亿个序列的多样化类图书馆是必不可少的.
- 翻译启动通常仅限于AUG开始编码子,限制了库的多样性.
研究的目的:
- 研究大肠杆菌核糖体启动翻译的能力,使用抗突变启动器tRNAs (tRNAini).
- 了解tRNA折叠如何影响翻译启动效率.
- 在mRNA显示库生成中设计tRNAini以增强功能.
主要方法:
- 利用NanoBiT翻译试验来测试31个tRNAini抗突变体.
- 引入了二次突变以恢复tRNA折叠并提高翻译效率.
- 在针对乌比基特异蛋白酶7 (USP7) 的宏环的突变分析中应用工程tRNAini.
主要成果:
- 突变tRNAini的启动效率是高度可变的,并且经常被tRNA错误折叠所抑制.
- 通过工程恢复tRNA活性折叠成功提高了翻译效率.
- 在USP7结合剂中的丰富与SPR测量的解离常数有很强的相关性.
结论:
- 在tRNAini中的Anticodon突变可以导致错误折叠和可变翻译启动.
- 工程tRNA结构可以克服启动缺陷,并实现更广泛的库多样性.
- 这种方法使得无需合成的结剂的结构-活性关系研究更容易.
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