具有异常二级结构的线粒体tRNA的翻译活性。

Translation activity of mitochondrial tRNA with unusual secondary structure.

作者信息

Hanada T, Suzuki T, Watanabe K

机构信息

Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

出版信息

Nucleic Acids Symp Ser. 2000(44):249-50. doi: 10.1093/nass/44.1.249.

DOI:10.1093/nass/44.1.249

PMID:12903362

Abstract

Mammalian mitochondrial translation system requires two serine isoacceptor tRNAs, tRNA(Ser)GCU and tRNA(Ser)UGA, which correspond to codons AGY (Y = U or C) and UCN (N = A, G, C or U), respectively. Each tRNA has unusual secondary structure; tRNA(Ser)GCU lacks the entire D arm, while tRNA(Ser)UGA has a slightly varied cloverleaf structure with an extended anticodon stem. The translation activity of these tRNAs(Ser) was examined by using their transcripts produced by T7 RNA polymerase and an in vitro mitochondrial translation system, showing that tRNA(Ser)GCU has much lower translation ability than that of tRNA(Ser)UGA. HPLC analysis of the product suggested that a certain rate limiting step should exist in the elongation cycle of translation with tRNA(Ser)GCU.

摘要

哺乳动物线粒体翻译系统需要两种丝氨酸同工受体tRNA，即tRNA(Ser)GCU和tRNA(Ser)UGA，它们分别对应密码子AGY（Y = U或C）和UCN（N = A、G、C或U）。每种tRNA都具有不寻常的二级结构；tRNA(Ser)GCU缺少整个D臂，而tRNA(Ser)UGA具有略有不同的三叶草结构，其反密码子茎延长。通过使用T7 RNA聚合酶产生的转录本和体外线粒体翻译系统来检测这些tRNA(Ser)的翻译活性，结果表明tRNA(Ser)GCU的翻译能力远低于tRNA(Ser)UGA。对产物的HPLC分析表明，在使用tRNA(Ser)GCU进行翻译的延伸循环中应该存在某个限速步骤。