没有专用停止符号的遗传代码:上下文依赖的翻译终止
Estienne Carl Swart1, Valentina Serra2, Giulio Petroni2
1Institute of Cell Biology, University of Bern, 3012 Bern, Switzerland.
Cell
|July 19, 2016
概括
核遗传密码没有固定. 一些类动物使用停止子作为氨基酸,挑战标准的遗传密码,并建议mRNA 3'末端有助于调节翻译终结.
科学领域:
- 分子生物学
- 遗传学
- 进化生物学
背景情况:
- 核遗传密码传统上被认为是高度保存和明确的.
- 变异存在,特别是在毛动物中,它们可以将停止编码重新分配给感觉编码,从而导致变异的遗传代码.
研究的目的:
- 研究毛动物中阻断子重新分配的机制.
- 探索翻译机器如何在变异性遗传密码中区分停止密码和感觉密码.
- 了解mRNA 3'在遗传代码进化中的作用.
主要方法:
- 使用核糖体分析来分析翻译动态.
- 在编码序列末端进行了停止密码子使用和耗尽模式的分析.
主要成果:
- 在毛动物中发现了七种变异性遗传密码,其中包括三种新型.
- 在两种物种中,所有64个编码子都被有效地转化为标准氨基酸,识别了一个或所有停止编码子.
- 有证据表明mRNA 3'末端有助于上下文依赖的停止子识别.
结论:
- 停止子重新分配比之前认为的更为普遍.
- 可能涉及mRNA 3'末端的上下文依赖机制在调节翻译终结和阅读中起着至关重要的作用.
- 这些机制促进了基因代码的演变和新基因代码的出现.
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