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伪乌里丁合成酶通过催化和重塑两种方式塑造tRNA结构动态

Emily M Dennis^1,2, Nico E Conoan Nieves², Abigail L Vaaler¹

¹Institute of Molecular Biology, University of Oregon, Eugene, OR, 97403, USA.

bioRxiv : the preprint server for biology

|July 14, 2025

概括

转移RNA (tRNA) 动态样本的形状. 酶Pus4/TruB在结合后重塑tRNA结构,伪尿化加速了这一过程并影响了酶活性.

科学领域:

分子生物学分子生物学
生物化学生物化学
结构生物学是结构生物学.

背景情况:

转移RNA (tRNA) 是一个以其稳定性和结构而闻名的关键分子.
在与修饰酶相互作用时,tRNA经历了显著的结构变化.
了解这些动态是tRNA成熟和功能的关键.

研究的目的:

调查tRNA在与伪尿素合成酶Pus4/TruB.交互之前和之后的结构动态.
阐明伪氨基化在tRNA构成和Pus4/TruB结合中的作用.
为了比较野生类型Pus4/TruB和催化不活跃突变物对tRNA结构的影响.

主要方法:

用光学结合测试来研究分子相互作用.
用单分子弗斯特共振能量转移 (smFRET) 来观察tRNA结构动态.
在Pus4/TruB.的存在和缺席下分析了tRNA的整合状态.

主要成果:

未经修改和伪尿化tRNA动态样本的开放和闭合形状.
Pus4/TruB与未经修改的tRNA结合会诱导额外的构造状态.
在Pus4/TruB参与时,预伪基化tRNA更快地接近最终的形状组合.
与野生类型酶相比,一种催化不活跃的Pus4/TruB突变体表现出较慢的结合,并诱导出明显的形状组合.

结论:

Pus4/TruB催化了tRNA上的化学修饰,并诱导了持久的结构变化.
该酶与tRNA的相互作用是动态的,并影响随后的tRNA成熟步骤.
伪化在调节tRNA构造和Pus4/TruB活性方面发挥着重要作用.

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