Recognition by tryptophanyl-tRNA synthetases of discriminator base on tRNATrP from three biological domains
Recognition by tryptophanyl-tRNA synthetases of discriminator base on tRNATrP from three biological domains
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DOI：
10.1074/jbc.m111745200
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发表时间：
2002-04-19
影响因子：
4.8
通讯作者：
Xue, H
中科院分区：
文献类型：
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作者：
Guo, Q;Gong, QG;Xue, H
为了研究色氨酸-tRNA合成酶（TrpRS）对tRNA（Trp）鉴别碱基的识别，将突变引入枯草芽孢杆菌（Bacillus subtilis）、黄舌原孢（archeglobus fulgidus）和牛tRNA（Trp）的鉴别碱基中，分别代表三个生物结构域。当用枯草芽孢杆菌、赤霉病杆菌和人类trpr对这些tRNA（Trp）进行酰化时，发现不同tRNA（Trp）底物的鉴别基有两个不同的偏好谱：枯草芽孢杆菌的trpr为G>A>U>C，赤霉病芽孢杆菌和人类的trpr为A>C>U>G。细菌trpr对tRNA（Trp）中G73的偏好远强于古细菌和真核生物trpr对A73的适度偏好。这三个结构域的trpr和tRNA（Trp）的跨物种反应性符合古细菌处于真核生物和细菌之间的进化位置的观点。核磁共振发现，牛tRNA（Trp）中A73 - G73突变引起G1-C72碱基对构象改变。G1-C72突变为A1-U72或G1-C72碱基对断裂也会导致Trp- trna （Trp）形成减少。这些观察结果表明，在受体链末端有一个由A73和G1-C72组成的tRNA（Trp）结构区域，是人类trpr有效识别所需的关键结构域。
To study the recognition by tryptophanyl-tRNA synthetase (TrpRS) of tRNA(Trp) discriminator base, mutations were introduced into the discriminator base of Bacillus subtilis, Archeoglobus fulgidus, and bovine tRNA(Trp), representing the three biological domains. When B. subtilis, A fulgidus, and human TrpRS were used to acylate these tRNA(Trp), two distinct preference profiles regarding the discriminator base of different tRNA(Trp) substrates were found: G>A>U>C for B. subtilis TrpRS, and A>C>U>G for A. fulgidus and human TrpRS. The preference for G73 in tRNA(Trp) by bacterial TrpRS is much stronger than the modest preferences for A73 by the archaeal and eukaryotic TrpRS. Cross-species reactivities between TrpRS and tRNA(Trp) from the three domains were in accordance with the view that the evolutionary position of archaea is intermediate between those of eukarya and bacteria. NMR spectroscopy revealed that mutation of A73 to G73 in bovine tRNA(Trp) elicited a conformational alteration in the G1-C72 base pair. Mutation of G1-C72 to A1-U72 or disruption of the G1-C72 base pair also caused reduction of Trp-tRNA(Trp) formation. These observations identify a tRNA(Trp) structural region near the end of acceptor stem comprising A73 and G1-C72 as a crucial domain required for effective recognition by human TrpRS.