Crystal structure of the tRNA 3′ processing endoribonuclease tRNase Z from Thermotoga maritima
Crystal structure of the tRNA 3′ processing endoribonuclease tRNase Z from Thermotoga maritima
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DOI：
10.1074/jbc.m500355200
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发表时间：
2005-04-08
影响因子：
4.8
通讯作者：
Yokoyama, S
中科院分区：
文献类型：
--
作者：
Ishii, R;Minagawa, A;Yokoyama, S
在真核生物、古生菌和一些细菌中，tRNA 3 ‘末端的成熟是由tRNA 3 ’加工核糖核酸内酶tRNase Z （RNase Z或3 '- tRNase）催化的。tRNase Z通常在鉴别核苷酸之后从前体tRNA上剪切3 '的额外序列。相比之下，Thermotoga martima tRNase Z在CCA序列之后精确地切割前体tRNA。在这项研究中，我们在2.6埃分辨率下测定了T. maritima tRNase Z的晶体结构。tRNase Z具有四层α β / β α夹心折叠，被归类为金属- β -内酰胺酶折叠，并形成二聚体。活性位点位于-三明治的一个边缘，由保守基序组成。基于该结构，我们构建了一个与trna的对接模型，该模型表明tRNase Z如何识别底物trna。
The maturation of the tRNA 3 ' end is catalyzed by a tRNA 3 ' processing endoribonuclease named tRNase Z ( RNase Z or 3 '- tRNase) in eukaryotes, Archaea, and some bacteria. The tRNase Z generally cuts the 3 ' extra sequence from the precursor tRNA after the discriminator nucleotide. In contrast, Thermotoga maritima tRNase Z cleaves the precursor tRNA precisely after the CCA sequence. In this study, we determined the crystal structure of T. maritima tRNase Z at 2.6-angstrom resolution. The tRNase Z has a four- layer alpha beta/beta alpha sandwich fold, which is classified as a metallo- beta- lactamase fold, and forms a dimer. The active site is located at one edge of the beta- sandwich and is composed of conserved motifs. Based on the structure, we constructed a docking model with the tRNAs that suggests how tRNase Z may recognize the substrate tRNAs.