来自面包酵母的缬氨酰 - 转运RNA、异亮氨酰 - 转运RNA和酪氨酰 - 转运RNA合成酶。关于ATP类似物的底物特异性及氨酰化反应机制。

Valyl-tRNA, isoleucyl-tRNA and tyrosyl-tRNA synthetase from baker's yeast. Substrate specificity with regard to ATP analogs and mechanism of the aminoacylation reaction.

作者信息

Freist W, von der Haar F, Faulhammer H, Cramer F

出版信息

Eur J Biochem. 1976 Jul 15;66(3):493-7. doi: 10.1111/j.1432-1033.1976.tb10574.x.

DOI:10.1111/j.1432-1033.1976.tb10574.x

Abstract

Nineteen analogs of ATP have been tested in the aminoacylation of valyl-tRNA, isoleucyl tRNA and tyrosyl-tRNA synthetases from baker's yeast. Four compounds are substrates for valyl tRNA and two for isoleucyl-tRNA synthetase, but there is no modified substrate for the tyrosyl tRNA synthetase. There is one inhibitor for valyl-tRNA synthetase, eight compounds inhibit isoleucyl-tRNA synthetase and two compounds inhibit tyrosyl-tRNA synthetase. Their Km and Ki and V values have been determined. The substrate specificity shows that positions 2, 6, 7, 8, 9, 2', and 3' of ATP are important for catalytic action of these aminoacyl-tRNA synthetases.

摘要

已对19种ATP类似物在面包酵母的缬氨酰 - tRNA、异亮氨酰 - tRNA和酪氨酰 - tRNA合成酶的氨酰化反应中进行了测试。有4种化合物是缬氨酰 - tRNA合成酶的底物，2种是异亮氨酰 - tRNA合成酶的底物，但没有酪氨酰 - tRNA合成酶的修饰底物。有1种化合物是缬氨酰 - tRNA合成酶的抑制剂，8种化合物抑制异亮氨酰 - tRNA合成酶，2种化合物抑制酪氨酰 - tRNA合成酶。已测定了它们的Km、Ki和V值。底物特异性表明，ATP的第2、6、7、8、9、2'和3'位对这些氨酰 - tRNA合成酶的催化作用很重要。