没有RNA的RNase P:人类线粒体tRNA处理酶的识别和功能复合
Johann Holzmann1, Peter Frank, Esther Löffler
1Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria.
Cell
|November 6, 2008
概括
人类线粒体RNase P,对于tRNA成熟至关重要,是一种仅蛋白质的酶,而不是 ribozyme-catalyzed. 这一发现揭示了线粒体重新利用现有的蛋白质,失去祖先的RNA成分.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 转移RNA (tRNA) 对于蛋白质合成至关重要,最初作为前体分子合成.
- RNase P酶是必不可少的内核酶,可以从tRNA前的5'领导序列中去除以成熟.
- 以前,已知所有特征化的RNase P酶都含有RNA成分,作为 ribozymes 起作用.
研究的目的:
- 为了识别人类线粒体RNase P.的组成部分.
- 复制和描述人类线粒体RNase P.的酶活性.
- 为了确定是否需要RNA用于人类线粒体RNase P催化.
主要方法:
- 使用组合净化和蛋白质学方法来识别人类线粒体RNase P组件.
- 使用三种纯化的重组蛋白质重构酶活性.
- 描述了复制酶的催化机制和成分要求.
主要成果:
- 人类线粒体RNase P从三个蛋白质组成部分重组.
- 复制后的酶显示了tRNA 5'端处理活性.
- 催化被证实是基于蛋白质的,独立于任何RNA分子.
- 该酶包括一个tRNA甲基转移酶,一个短链脱酶/还原酶家族成员,以及一种新型蛋白质.
结论:
- 人类线粒体RNase P是一种仅含蛋白质的酶,挑战了普遍的核糖酶模型.
- 线粒体通过利用现有的蛋白质机制,进化出一种新的RNA独立RNase P.
- 这一发现表明,动物线粒体中遗传的RNA成分已经消失,其功能被蛋白质替代.
相关概念视频
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02:47Ribozymes
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01:39Mitochondrial Protein Sorting
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02:43Nucleic acids
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DNA and RNA
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02:43Nucleic Acids
Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning.
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the...
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the...