对具有长可变臂的大肠杆菌转运RNA进行区分。

Discrimination among E. coli tRNAs with a long variable arm.

作者信息

Asahara H, Himeno H, Tamura K, Nameki N, Hasegawa T, Shimizu M

机构信息

Institute of Space and Astronautical Science, Kanagawa, Japan.

出版信息

Nucleic Acids Symp Ser. 1993(29):207-8.

PMID:7504246

Abstract

In E. coli, tRNA(Ser), tRNA(Leu) and tRNA(Tyr) have a long variable arm composed of more than ten nucleotides (class II tRNAs). In order to study how leucyl- and seryl-tRNA synthetase discriminate their cognate tRNA isoacceptors from the other class II tRNAs, kinetic parameters of various mutated class II tRNA transcripts with leucyl- and seryl-tRNA synthetase were determined. Leucyl-tRNA synthetase recognizes A73 and A14 or its vicinity. Seryl-tRNA synthetase recognizes the long variable arm base-nonspecifically. C2-G71 in the acceptor stem functions as a negative identity element against seryl-tRNA synthetase. Difference in the tertiary structure among class II tRNA molecules plays a crucial role in discrimination by these two synthetases.

摘要

在大肠杆菌中，tRNA(Ser)、tRNA(Leu)和tRNA(Tyr)具有由十多个核苷酸组成的长可变臂（II类tRNA）。为了研究亮氨酰-tRNA合成酶和丝氨酰-tRNA合成酶如何将其同源tRNA同工受体与其他II类tRNA区分开来，测定了各种突变的II类tRNA转录本与亮氨酰-tRNA合成酶和丝氨酰-tRNA合成酶的动力学参数。亮氨酰-tRNA合成酶识别A73和A14或其附近区域。丝氨酰-tRNA合成酶非特异性地识别长可变臂。受体茎中的C2-G71作为针对丝氨酰-tRNA合成酶的负性识别元件。II类tRNA分子之间三级结构的差异在这两种合成酶的识别中起关键作用。