密码子上下文对体外UGU密码子错译的影响。

An effect of codon context on the mistranslation of UGU codons in vitro.

作者信息

Carrier M J, Buckingham R H

出版信息

J Mol Biol. 1984 May 5;175(1):29-38. doi: 10.1016/0022-2836(84)90443-1.

Abstract

Effects of codon context on nonsense codon suppression may act either through release factor recognition of termination codons or aminoacyl-tRNA selection by the ribosome. The latter hypothesis has been studied by comparing misreading by Escherichia coli UGA suppressor tryptophan tRNA of UGU (cysteine) codons in two synthetic polymers, poly(U-G) and poly( U5 , G), which differ in sequence around the UGU codons. In vitro translation of these polymers in a cell-free system from E. coli yielded selection errors of 4 X 10(-3) and 1.75 X 10(-2) for UGU codons in poly(U-G) and poly( U5 , G), respectively. This difference suggests that codon context may significantly affect misincorporation of amino acids into protein.

摘要

密码子上下文对无义密码子抑制的影响可能通过终止密码子的释放因子识别或核糖体对氨酰 - tRNA的选择来发挥作用。后一种假设已通过比较大肠杆菌UGA抑制型色氨酸tRNA对两种合成聚合物poly(U - G)和poly(U5, G)中UGU（半胱氨酸）密码子的错读进行了研究，这两种聚合物在UGU密码子周围的序列不同。在来自大肠杆菌的无细胞系统中对这些聚合物进行体外翻译，结果显示poly(U - G)和poly(U5, G)中UGU密码子的选择错误分别为4×10⁻³和1.75×10⁻²。这种差异表明密码子上下文可能会显著影响氨基酸错误掺入蛋白质的情况。