A snapshot of the 30S ribosomal subunit capturing mRNA via the Shine-Dalgarno interaction
A snapshot of the 30S ribosomal subunit capturing mRNA via the Shine-Dalgarno interaction
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DOI：
10.1016/j.str.2006.12.008
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发表时间：
2007-03-01
期刊：
影响因子：
5.7
通讯作者：
Yokoyama, Shigeyuki
中科院分区：
文献类型：
--
作者：
Kaminishi, Tatsuya;Wilson, Daniel N.;Yokoyama, Shigeyuki
在细菌翻译的起始阶段，30 S核糖体亚基捕获mRNA，准备与起始tRNA结合。富含嘌呤的Shine-Dalgarno（SD）序列位于mRNA的5'非翻译区，通过与16 S rRNA 3'末端的抗SD（aSD）序列进行碱基配对，将30 S亚基锚定在起始密码子附近。在这里，我们提出了3.3埃的晶体结构的嗜热栖热菌30 S亚基结合的mRNA模拟。由SD和aSD序列形成的双链体紧密地对接在头部和平台结构域之间的“腔室”中，证明了30 S亚基如何捕获和稳定原本不稳定的SD螺旋。SD螺旋的这个位置适合于将起始密码子AUG放置在紧邻mRNA通道的位置，这与起始密码子的第二个位置和16 S rRNA的G1530之间的报告的交联一致。
In the initiation phase of bacterial translation, the 30S ribosomal subunit captures mRNA in preparation for binding with initiator tRNA. The purine-rich Shine-Dalgarno (SD) sequence, in the 5' untranslated region of the mRNA, anchors the 30S subunit near the start codon, via base pairing with an anti-SD (aSD) sequence at the 3' terminus of 16S rRNA. Here, we present the 3.3 angstrom crystal structure of the Thermus thermophilus 30S subunit bound with an mRNA mimic. The duplex formed by the SD and aSD sequences is snugly docked in a "chamber" between the head and platform domains, demonstrating how the 30S subunit captures and stabilizes the otherwise labile SD helix. This location of the SD helix is suitable for the placement of the start codon AUG in the immediate vicinity of the mRNA channel, in agreement with reported crosslinks between the second position of the start codon and G1530 of 16S rRNA.