原始的氨基-tRNA合成酶更喜欢小型螺旋,而不是全长的tRNA
Guo Qing Tang1, Hao Hu1, Jordan Douglas2,3,4
1Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA.
Nucleic acids research
|May 23, 2024
概括
这项研究表明,祖先的氨基酸-tRNA合成酶 (AARS) 酶和tRNA小螺旋体可能已经强制执行了遗传编码规则. 这些简单的分子对作为早期解码机制的模型.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 生命的起源 生命的起源
背景情况:
- 氨基酸-tRNA合成酶 (AARS) 和tRNA对于翻译遗传密码至关重要.
- 这些分子如何建立编码规则的进化起源尚未得到充分理解.
- 一个以前的假设表明,AARS催化域最初在tRNA受体茎内读取一个"操作"代码.
研究的目的:
- 为了调查早期AARS酶利用了可操作的RNA代码的假设.
- 为了探索祖先AARS-tRNA小螺旋相互作用的酶学.
- 建立一个模型系统来研究遗传密码的进化.
主要方法:
- 氨基酸-tRNA合成酶酶 (LeuAC) 和一个TΨC-迷你RNA基质的体外表征.
- 使用截断的tRNA小螺旋体 (TΨC-minihelixLeu) 评估基质特异性.
- 对LeuAC活性部位的突变性研究,以分析基质选择.
主要成果:
- 对于全长的Leucyl-tRNA合成酶来说,TΨC-minihelixLeu是一个糟糕的基质,但对于LeuACurzyme来说,它是一个优秀的基质.
- 在LeuAC活性部位的突变改变了氨基酸和RNA基质的偏好.
- 这些发现支持了由AARSurzyme-minihelix对介导的操作RNA代码的概念.
结论:
- AARS urzyme•minihelix 亲属对代表了可信的早期形式的遗传解码机器.
- 这些系统为研究操作RNA代码提供了一个可操作的实验平台.
- 这项研究提供了关于蛋白质合成和遗传密码早期演变的见解.
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