真核生物释放因子3（eRF3）的C末端76个氨基酸对于八肋游仆虫（Euplotes octocarinatus）释放因子eRF1a的结合并非必需。

C-terminal 76 amino acids of eRF3 are not required for the binding of release factor eRF1a from Euplotes octocarinatus.

作者信息

Song Li, Wang Yuyao, Chai Baofeng, Wang Wei, Liang Aihua

机构信息

Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.

出版信息

J Genet Genomics. 2007 Jun;34(6):486-90. doi: 10.1016/S1673-8527(07)60053-8.

DOI:10.1016/S1673-8527(07)60053-8

Abstract

Termination of translation in eukaryotes requires two polypeptide chain-release factors, eRF1 and eRF3. eRF1 recognizes stop signals, whereas eRF3 is a ribosome-dependent and eRF1-dependent GTPase. Polypeptide release factor eRF3 consists of N-terminal variable region and C-terminal conserved part. C-terminal part of eRF3 is responsible for termination of the translation. In the present study, the C-terminal of Euplotes octocarinatus eRF3 (eRF3C) and truncate eRF3C lacking 76 amino acids in C-terminal (eRF3Ct) were expressed in Escherichia coli. The recombinant GST-eRF3C and GST-eRF3Ct polypeptides were purified by affinity chromatography using glutathione Sepharose 4B column. After enzymatic cleavage of GST tail, the eRF3C and eRF3Ct protein were obtained. Pull-down analysis showed that the recombinant GST-eRF3C and GST-eRF3Ct polypeptides interacted with E. octocarinatus polypeptide chain release factor eRF1a. This result suggested that the C-terminal of eRF3 having 76 amino acids were not required for the binding of eRF1a in Euplotes octocarinatus.

摘要

真核生物中的翻译终止需要两种多肽链释放因子，即eRF1和eRF3。eRF1识别终止信号，而eRF3是一种依赖核糖体且依赖eRF1的GTP酶。多肽释放因子eRF3由N端可变区和C端保守部分组成。eRF3的C端部分负责翻译的终止。在本研究中，八肋游仆虫eRF3的C端（eRF3C）和C端缺少76个氨基酸的截短型eRF3C（eRF3Ct）在大肠杆菌中表达。重组GST-eRF3C和GST-eRF3Ct多肽通过使用谷胱甘肽琼脂糖4B柱的亲和层析进行纯化。在对GST尾进行酶切后，获得了eRF3C和eRF3Ct蛋白。下拉分析表明，重组GST-eRF3C和GST-eRF3Ct多肽与八肋游仆虫多肽链释放因子eRF1a相互作用。该结果表明，八肋游仆虫中eRF1a的结合不需要具有76个氨基酸的eRF3的C端。