酵母苯丙氨酰 - tRNA合成酶对其同源酵母tRNA（Phe）的识别：特异性分析。

Recognition of yeast tRNA(Phe) by its cognate yeast phenylalanyl-tRNA synthetase: an analysis of specificity.

作者信息

Sampson J R, Behlen L S, DiRenzo A B, Uhlenbeck O C

机构信息

Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309.

出版信息

Biochemistry. 1992 May 5;31(17):4161-7. doi: 10.1021/bi00132a002.

DOI:10.1021/bi00132a002

PMID:1567862

Abstract

A kinetic analysis of aminoacylation of mutant yeast tRNA(Phe) transcripts by its cognate yeast phenylalanyl-tRNA synthetase (FRS) reveals five nucleotides in tRNA(Phe) as major recognition sites for FRS. The aminoacylation kinetics for two double mutants suggest that each of the five recognition sites contributes independently to kcat/KM. Measured kinetic values for the mutants presented here and those reported previously were then used to calculate the predicted kcat/KM of misacylation for a number of noncognate tRNAs. The predicted kcat/KM values are consistent with values measured by other investigators and thus support the five-nucleotide recognition model. The kcat/KM of misacylation for all known yeast tRNAs has been calculated on the basis of this model, and the specificity of FRS for tRNA(Phe) in yeast is discussed.

摘要

对突变型酵母苯丙氨酸转运RNA（tRNA(Phe)）转录本被其同源酵母苯丙氨酰tRNA合成酶（FRS）进行氨酰化的动力学分析表明，tRNA(Phe)中的五个核苷酸是FRS的主要识别位点。两个双突变体的氨酰化动力学表明，这五个识别位点中的每一个都对催化常数（kcat）与米氏常数（KM）的比值有独立贡献。然后，利用此处给出的突变体以及先前报道的突变体的测量动力学值，来计算许多非同源tRNA错配氨酰化的预测kcat/KM值。预测的kcat/KM值与其他研究者测量的值一致，因此支持了五核苷酸识别模型。基于该模型计算了所有已知酵母tRNA错配氨酰化的kcat/KM，并讨论了酵母中FRS对tRNA(Phe)的特异性。