Tertiary structure checkpoint at anticodon loop modification in tRNA functional maturation
Tertiary structure checkpoint at anticodon loop modification in tRNA functional maturation
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DOI：
10.1038/nsmb.1653
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发表时间：
2009-10-01
影响因子：
16.8
通讯作者：
Yokoyama, Shigeyuki
中科院分区：
文献类型：
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作者：
Goto-Ito, Sakurako;Ito, Takuhiro;Yokoyama, Shigeyuki
tRNA前体经历成熟过程，包括核苷酸修饰和折叠成L形三级结构。在位置37（m1 G37）的N1-甲基鸟苷，3'邻近反密码子，对于翻译保真度和效率是必需的。在古细菌和真核生物中，Trm 5将m（1）G37修饰引入所有携带G37的tRNA。在这里，我们报告的晶体结构的古菌Trm 5（aTrm 5）在复杂的tRNALeu或tRNACys。aTrm 5的D2-D3结构域独立于tRNA序列发现并修饰G37。D1通过一个柔性接头连接到D2-D3，并被设计为识别tRNA外角的形状，作为完成L形形成的标志。D1的这种相互作用降低了tRNA的Km值，使D2-D3催化成为可能。因此，我们认为aTrm 5在tRNA成熟中提供了三级结构检查点。
tRNA precursors undergo a maturation process, involving nucleotide modifications and folding into the L-shaped tertiary structure. The N1-methylguanosine at position 37 (m1G37), 3' adjacent to the anticodon, is essential for translational fidelity and efficiency. In archaea and eukaryotes, Trm5 introduces the m(1)G37 modification into all tRNAs bearing G37. Here we report the crystal structures of archaeal Trm5 (aTrm5) in complex with tRNALeu or tRNACys. The D2-D3 domains of aTrm5 discover and modify G37, independently of the tRNA sequences. D1 is connected to D2-D3 through a flexible linker and is designed to recognize the shape of the tRNA outer corner, as a hallmark of the completed L shape formation. This interaction by D1 lowers the Km value for tRNA, enabling the D2-D3 catalysis. Thus, we propose that aTrm5 provides the tertiary structure checkpoint in tRNA maturation.