Beresten S, Jahn M, Söll D
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
Nucleic Acids Res. 1992 Apr 11;20(7):1523-30. doi: 10.1093/nar/20.7.1523.
Aminoacyl-tRNA synthetases interact with their cognate tRNAs in a highly specific fashion. We have examined the phenomenon that upon complex formation E. coli glutaminyl-tRNA synthetase destabilizes tRNA(Gln) causing chain scissions in the presence of Mg2+ ions. The phosphodiester bond cleavage produces 3'-phosphate and 5'-hydroxyl ends. This kind of experiment is useful for detecting conformational changes in tRNA. Our results show that the cleavage is synthetase-specific, that mutant and wild-type tRNA(Gln) species can assume a different conformation, and that modified nucleosides in tRNA enhance the structural stability of the molecule.
氨酰-tRNA合成酶以高度特异性的方式与其对应的tRNA相互作用。我们研究了这样一种现象：在形成复合物时，大肠杆菌谷氨酰胺-tRNA合成酶会使tRNA(Gln)不稳定，在Mg2+离子存在的情况下导致链断裂。磷酸二酯键的断裂产生3'-磷酸和5'-羟基末端。这种实验对于检测tRNA的构象变化很有用。我们的结果表明，这种断裂是合成酶特异性的，突变型和野生型tRNA(Gln)种类可以呈现不同的构象，并且tRNA中的修饰核苷增强了分子的结构稳定性。
