Nureki O, Vassylyev D G, Katayanagi K, Shimizu T, Sekine S, Kigawa T, Miyazawa T, Yokoyama S, Morikawa K
Department of Biophysics and Biochemistry, School of Science, University of Tokyo, Japan.
Science. 1995 Mar 31;267(5206):1958-65. doi: 10.1126/science.7701318.
The crystal structure of a class I aminoacyl-transfer RNA synthetase, glutamyl-tRNA synthetase (GluRS) from Thermus thermophilus, was solved and refined at 2.5 A resolution. The amino-terminal half of GluRS shows a geometrical similarity with that of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) of the same subclass in class I, comprising the class I-specific Rossmann fold domain and the intervening subclass-specific alpha/beta domain. These domains were found to have two GluRS-specific, secondary-structure insertions, which then participated in the specific recognition of the D and acceptor stems of tRNA(Glu) as indicated by mutagenesis analyses based on the docking properties of GluRS and tRNA. In striking contrast to the beta-barrel structure of the GlnRS carboxyl-terminal half, the GluRS carboxyl-terminal half displayed an all-alpha-helix architecture, an alpha-helix cage, and mutagenesis analyses indicated that it had a role in the anticodon recognition.
嗜热栖热菌I类氨酰基转移RNA合成酶——谷氨酰胺-tRNA合成酶（GluRS）的晶体结构已得到解析，并在2.5埃分辨率下进行了优化。GluRS的氨基末端一半与I类同一亚类的大肠杆菌谷氨酰胺-tRNA合成酶（GlnRS）的氨基末端一半在几何结构上相似，包括I类特异性的Rossmann折叠结构域和中间的亚类特异性α/β结构域。这些结构域被发现有两个GluRS特异性的二级结构插入片段，基于GluRS与tRNA的对接特性进行的诱变分析表明，它们参与了对tRNA（Glu）的D茎和受体茎的特异性识别。与GlnRS羧基末端一半的β桶结构形成鲜明对比的是，GluRS羧基末端一半呈现出全α螺旋结构，即一个α螺旋笼，诱变分析表明它在反密码子识别中起作用。
