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在tRNA修饰中选择性甲基化5-碳素甲基尤里丁的结构基础
Jaehun Yoo1, Jangmin Lee1, Jungwook Kim1
1Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
Nucleic acids research
|August 17, 2023
概括
细菌tRNA的修饰涉及到由CmoM甲基化的5-carboxymethoxyuridine. 晶体结构揭示了CmoM如何识别特定的tRNA特征,例如34位的5-carboxymethoxyuridine,以获得准确的甲基化.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生化学
背景情况:
- 转移RNA (tRNA) 的转录后修饰对于所有生命领域的细胞功能至关重要.
- 抗的修改,特别是那些涉及5-基尤里丁衍生物的修改,显著影响翻译效率.
- 在细菌中,5-甲基尤里丁和5-碳素甲基尤里丁是普遍存在的,后者被CmoM进一步修改.
研究的目的:
- 阐明CmoM介导的tRNA甲基化的结构基础.
- 了解CmoM对其基质tRNA的分子识别机制.
- 提供有关tRNA修饰酶的特异性的见解.
主要方法:
- 使用X射线晶体学来确定与tRNASer1.1复合的Escherichia coli CmoM酶的结构.
- 进行了高分辨率结构分析 (2.22 Å),以检查蛋白质-tRNA相互作用.
- 结合界面上的构造变化和基相互作用的分析.
主要成果:
- 结晶结构揭示了复杂形成后CmoM和tRNASer1的局部构造变化.
- 在位置34的5-carboxymethoxyuridine基被翻转出来,促进与酶的特定相互作用.
- CmoM特别识别了抗手臂,确定了5 - 碳素甲基尤里丁在位置34和瓜诺辛在位置35的关键决定因素.
结论:
- 这项研究为CmoM对非同类tRNA的基质歧视提供了分子基础.
- 结构洞察力解释了CmoM如何精确地准特定的tRNA分子进行甲基化.
- 这项工作增强了对控制tRNA转录后修饰的复杂机制及其在翻译调节中的作用的理解.
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