McClain W H, Schneider J, Gabriel K
Department of Bacteriology, University of Wisconsin, Madison 53706-1567.
Biochimie. 1993;75(12):1125-36. doi: 10.1016/0300-9084(93)90012-h.
We isolated several mutants with nucleotide substitutions in alanine tRNA (tRNA(Ala)) that resulted in glutamine tRNA (tRNA(Gln)) acceptor identity in Escherichia coli. These substitutions were in three regions of tRNA structure not previously associated with tRNA(Gln) acceptor identity. Only the phosphate-sugar backbone moieties of these nucleotides interact with the enzyme in the previously determined X-ray crystal structure of the complex between tRNA(Gln) and glutaminyl-tRNA synthetase. We conclude that these sequence-dependent phosphate-sugar backbone interactions contribute to tRNA(Gln) identity, and argue that the interactions help communicate enzyme recognition of the anticodon to the acceptor end of the tRNA and the catalytic center of the enzyme.
我们在大肠杆菌中分离出了几个丙氨酸转运RNA（tRNA(Ala)）发生核苷酸替换的突变体，这些替换导致了谷氨酰胺转运RNA（tRNA(Gln)）的受体识别特性。这些替换发生在tRNA结构中之前与tRNA(Gln)受体识别特性无关的三个区域。在之前确定的tRNA(Gln)与谷氨酰胺-tRNA合成酶复合物的X射线晶体结构中，只有这些核苷酸的磷酸-糖主链部分与该酶相互作用。我们得出结论，这些序列依赖性的磷酸-糖主链相互作用有助于tRNA(Gln)的识别特性，并认为这些相互作用有助于将酶对反密码子的识别传递到tRNA的受体末端和酶的催化中心。
