Abstract

Translation termination is a finishing step of protein biosynthesis. The significant role in this process belongs not only to protein factors of translation termination but also to the nearest nucleotide environment of stop codons. There are numerous descriptions of stop codons readthrough, which is due to specific nucleotide sequences behind them. However, represented data are segmental and don’t explain the mechanism of the nucleotide context influence on translation termination. It is well known that stop codon UAA usage is preferential for A/T-rich genes, and UAG, UGA—for G/C-rich genes, which is related to an expression level of these genes. We investigated the connection between a frequency of nucleotides occurrence in 3' area of stop codons in the human genome and their influence on translation termination efficiency. We found that 3' context motif, which is cognate to the sequence of a stop codon, stimulates translation termination. At the same time, the nucleotide composition of 3' sequence that differs from stop codon, decreases translation termination efficiency.

中文翻译：

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3'终止密码子上下文的A / G组成对真核生物翻译终止效率的影响

摘要

翻译终止是蛋白质生物合成的最后步骤。在该过程中的重要作用不仅属于翻译终止的蛋白质因子，而且还属于终止密码子的最近核苷酸环境。终止密码子通读的描述很多，这是由于它们后面的特定核苷酸序列引起的。但是，表示的数据是分段的，不能解释核苷酸上下文影响翻译终止的机制。众所周知，终止密码子UAA的使用优先于富含A / T的基因，而UAG，UGA优先于富含G / C的基因，这与这些基因的表达水平有关。我们调查了人类基因组中终止密码子3'区域中核苷酸发生频率与它们对翻译终止效率的影响之间的联系。我们发现与终止密码子序列同源的3'上下文基序刺激翻译终止。同时，不同于终止密码子的3'序列的核苷酸组成降低了翻译终止效率。