Moulinier L, Eiler S, Eriani G, Gangloff J, Thierry J C, Gabriel K, McClain W H, Moras D
UPR 9004, Laboratoire de Biologie et Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 rue Laurent Fries, BP 163, 67404 Illkirch Cedex, France.
EMBO J. 2001 Sep 17;20(18):5290-301. doi: 10.1093/emboj/20.18.5290.
The 2.6 A resolution crystal structure of an inactive complex between yeast tRNA(Asp) and Escherichia coli aspartyl-tRNA synthetase reveals the molecular details of a tRNA-induced mechanism that controls the specificity of the reaction. The dimer is asymmetric, with only one of the two bound tRNAs entering the active site cleft of its subunit. However, the flipping loop, which controls the proper positioning of the amino acid substrate, acts as a lid and prevents the correct positioning of the terminal adenosine. The structure suggests that the acceptor stem regulates the loop movement through sugar phosphate backbone- protein interactions. Solution and cellular studies on mutant tRNAs confirm the crucial role of the tRNA three-dimensional structure versus a specific recognition of bases in the control mechanism.
酵母天冬氨酸转运核糖核酸(tRNA(Asp))与大肠杆菌天冬氨酰 - tRNA合成酶之间非活性复合物的2.6埃分辨率晶体结构揭示了一种由tRNA诱导的控制反应特异性机制的分子细节。该二聚体不对称,两个结合的tRNA中只有一个进入其亚基的活性位点裂隙。然而,控制氨基酸底物正确定位的翻转环起到盖子的作用,阻止了末端腺苷的正确定位。该结构表明,受体茎通过糖磷酸骨架 - 蛋白质相互作用调节环的运动。对突变tRNA的溶液和细胞研究证实了tRNA三维结构相对于碱基特异性识别在控制机制中的关键作用。