Liu Qingpo
Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China.
Biosystems. 2005 Sep;81(3):281-9. doi: 10.1016/j.biosystems.2005.05.005.
Using full-length cDNA sequences, a comparative analysis of sequence patterns around the stop codons in six eukaryotes was performed. Here, it was showed that the codon immediately before and after the stop codons (defined as -1 codon and +1 codon, respectively) were much more biased than other examined positions, especially at the second position of -1 codons and the first position of +1 codons which were rich in As/Us and purines, respectively, for most species. The author speculated that strongly biased sequence pattern from position -2 to +4 might act as an extended translation termination signal. Translation termination was catalyzed by release factors that recognized the stop codons. The multiple amino acid sequence alignment of eukaryotic release factor 1 (eRF1) of 20 species showed that there were 16 residue sites that were strictly conserved, especially the invariant amino acids Ile70 and Lys71. Accordingly, it could be inferred that those candidate amino acids might involve in the recognition process. Moreover, the possible stop signal recognition hypothesis was also discussed herein.
利用全长cDNA序列，对六种真核生物终止密码子周围的序列模式进行了比较分析。在此研究中发现，终止密码子之前和之后的密码子（分别定义为-1密码子和+1密码子）比其他检测位置的偏向性更强，特别是对于大多数物种而言，-1密码子的第二位富含A/U，+1密码子的第一位富含嘌呤。作者推测，从-2到+4位置的强烈偏向性序列模式可能作为一个扩展的翻译终止信号。翻译终止由识别终止密码子的释放因子催化。对20种真核生物释放因子1（eRF1）的多氨基酸序列比对表明，有16个残基位点严格保守，特别是不变氨基酸Ile70和Lys71。因此，可以推断这些候选氨基酸可能参与识别过程。此外，本文还讨论了可能的终止信号识别假说。
