转运信使核糖核酸（tmRNA）中的四个假结中有三个是可互换的，并且可以被单链核糖核酸替代。

Three of four pseudoknots in tmRNA are interchangeable and are substitutable with single-stranded RNAs.

作者信息

Nameki N, Tadaki T, Himeno H, Muto A

机构信息

Department of Biology, Faculty of Science, Hirosaki University, Hirosaki, Japan.

出版信息

FEBS Lett. 2000 Mar 31;470(3):345-9. doi: 10.1016/s0014-5793(00)01349-1.

DOI:10.1016/s0014-5793(00)01349-1

PMID:10745094

Abstract

A novel translation, trans-translation, is facilitated by a highly structured RNA molecule, tmRNA. This molecule has two structural domains, a tRNA domain and an mRNA domain, the latter including four pseudoknot structures (PK1 to PK4). Here, we show that replacement of each of these pseudoknots, except PK1, in Escherichia coli tmRNA with a single stranded RNA did not seriously affect the functions as an alanine tRNA and as an mRNA. Furthermore, these three pseudoknots were interchangeable with only small losses of the two functions. These findings suggest that neither PK2, PK3 nor PK4 interacts in a functional manner with ribosome during the trans-translation process. Together with an earlier study showing the significance of PK1, it is concluded that among the four pseudoknots, PK1 is the most functional.

摘要

一种新型的翻译，即反式翻译，由一种高度结构化的RNA分子——转运信使RNA（tmRNA）促成。该分子有两个结构域，一个tRNA结构域和一个mRNA结构域，后者包括四个假结结构（PK1至PK4）。在此，我们表明，在大肠杆菌tmRNA中，用单链RNA替换除PK1之外的每一个假结，对其作为丙氨酸tRNA和作为mRNA的功能没有严重影响。此外，这三个假结可以互换，且这两种功能仅有少量损失。这些发现表明，在反式翻译过程中，PK2、PK3和PK4均未以功能性方式与核糖体相互作用。结合早期一项显示PK1重要性的研究，得出的结论是，在这四个假结中，PK1的功能最强。