Tertiary structure base pairs between D- and TψC-loops of Escherichia coli tRNALeu play important roles in both aminoacylation and editing
Tertiary structure base pairs between D- and TψC-loops of Escherichia coli tRNALeu play important roles in both aminoacylation and editing
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DOI：
10.1093/nar/gkg382
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发表时间：
2003-06-01
影响因子：
14.9
通讯作者：
Wang, ED
中科院分区：
文献类型：
--
作者：
Du, X;Wang, ED
为了确保蛋白质生物合成的保真度，氨酰-tRNA合成酶（aaRSs）必须识别其同源tRNA的tRNA身份元件，并通过校对（编辑）反应将其同源氨基酸与结构相似的氨基酸区分开来。为了更好地理解这些过程，我们研究了tRNA（Leu）三级结构在亮氨酰-tRNA合成酶（LeuRS）催化的氨酰化和编辑反应中的作用。我们构建了一系列大肠杆菌tRNA（Leu）突变的转录本与三级相互作用中涉及的核苷酸的改变。我们的研究结果表明，任何干扰的tRNA（Leu）D-和TpsiC-环之间的三级相互作用影响其氨酰化的能力和刺激编辑反应的能力。此外，我们发现D-和TpsiC-环之间的各种三级相互作用（G18：U 55，G19：C56和U 54：A58）在氨酰化和编辑反应中的功能不同。在这两个反应中，碱基对19：56的作用密切相关，并依赖于氢键数。相比之下，U 54：A58在氨酰化中比在编辑中更重要。两者合计，我们的研究结果表明，由D-和TpsiC-环之间的三级相互作用形成的tRNA手肘区域有效地影响tRNA和阿尔斯之间的相互作用，在氨酰化和编辑。
To ensure the fidelity of protein biosynthesis, aminoacyl-tRNA synthetases (aaRSs) must recognize the tRNA identity elements of their cognate tRNAs and discriminate their cognate amino acids from structurally similar ones through a proofreading (editing) reaction. For a better understanding of these processes, we investigated the role of tRNA(Leu) tertiary structure in the aminoacylation and editing reactions catalyzed by leucyl-tRNA synthetase (LeuRS). We constructed a series of Escherichia coli tRNA(Leu) mutated transcripts with alterations of the nucleotides involved in tertiary interactions. Our results revealed that any disturbance of the tertiary interaction between the tRNA(Leu) D- and TpsiC-loops affected both its aminoacylation ability and its ability to stimulate the editing reaction. Moreover, we found that the various tertiary interactions between the D- and TpsiC-loops (G18:U55, G19:C56 and U54:A58) functioned differently within the aminoacylation and editing reactions. In these two reactions, the role of base pair 19:56 was closely correlated and dependent on the hydrogen bond number. In contrast, U54:A58 was more important in aminoacylation than in editing. Taken together, our results suggest that the elbow region of tRNA formed by the tertiary interactions between the D- and TpsiC-loops affects the interactions between tRNA and aaRS effectively both in aminoacylation and in editing.