一种用于将AUG三联体准确分配为甲硫氨酸的操作性RNA密码。

An operational RNA code for faithful assignment of AUG triplets to methionine.

作者信息

Jones Thomas E, Brown Cassidy L, Geslain Renaud, Alexander Rebecca W, Ribas de Pouplana Lluís

机构信息

Barcelona Institute for Research in Biomedicine, Barcelona Science Park, C/Samitier 1-5, Barcelona 08015, Catalonia, Spain.

出版信息

Mol Cell. 2008 Feb 15;29(3):401-7. doi: 10.1016/j.molcel.2007.12.021.

DOI:10.1016/j.molcel.2007.12.021

PMID:18280245

Abstract

The assignment of AUG codons to methionine remains a central question of the evolution of the genetic code. We have unveiled a strategy for the discrimination among tRNAs containing CAU (AUG-decoding) anticodons. Mycoplasma penetrans methionyl-tRNA synthetase can directly differentiate between tRNA(Ile)(CAU) and tRNA(Met)(CAU) transcripts (a recognition normally achieved through the modification of anticodon bases). This discrimination mechanism is based only on interactions with the acceptor stems of tRNA(Ile)(CAU) and tRNA(Met)(CAU). Thus, in certain species, the fidelity of translation of methionine codons requires a discrimination mechanism that is independent of the information contained in the anticodon.

摘要

将AUG密码子指定为甲硫氨酸仍然是遗传密码进化的核心问题。我们揭示了一种区分含有CAU（AUG解码）反密码子的tRNA的策略。穿透支原体甲硫氨酰-tRNA合成酶可以直接区分tRNA（Ile）（CAU）和tRNA（Met）（CAU）转录本（这种识别通常通过反密码子碱基的修饰来实现）。这种区分机制仅基于与tRNA（Ile）（CAU）和tRNA（Met）（CAU）的受体茎的相互作用。因此，在某些物种中，甲硫氨酸密码子翻译的保真度需要一种独立于反密码子中所含信息的区分机制。