Functional shine-dalgarno-like sequences for translational initiation of chloroplast mRNAs
Functional shine-dalgarno-like sequences for translational initiation of chloroplast mRNAs
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DOI：
10.1093/pcp/pch002
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发表时间：
2004-01-01
影响因子：
4.9
通讯作者：
Sugiura, M
中科院分区：
文献类型：
--
作者：
Hirose, T;Sugiura, M
许多叶绿体 mRNA 在 5'-非翻译区具有 Shine-Dalgarno (SD) 样序列（通常为 GGAGG），但位置高度可变。使用同源体外翻译系统，我们评估了四种烟草叶绿体 mRNA 中 SD 样序列的翻译作用。 rbcL mRNA在与大肠杆菌中观察到的保守位置（相对于起始密码子为-12至-4）相似的位置处具有典型的SD样序列，并且发现该序列对于翻译是必需的。 atpE mRNA 的情况也是如此。然而，rps12 mRNA 和 petB mRNA 中的 SD 样序列分别距离起始密码子较远（-44 至 -42）和太近（-5 至 -2），并且这些序列对于翻译不是必需的。这些结果表明功能性 SD 样序列位于翻译起始密码子上游约 10 个核苷酸处。竞争分析证实，功能性 SD 样序列与叶绿体 16S rRNA 的 3' 末端相互作用。
Many of the chloroplast mRNAs possess Shine-Dalgarno (SD)-like sequences (typically GGAGG) in the 5'-untranslated regions, but the position is highly variable. Using a homologous in vitro translation system, we assessed the role for translation of SD-like sequences in four tobacco chloroplast mRNAs. The rbcL mRNA has a typical SD-like sequence at a position similar to the conserved position (-12 to -4 with respect to the start codon) observed in E. coli, and this sequence was found to be essential for translation. This was also the case for the atpE mRNA. However, SD-like sequences in the rps12 mRNA and in the petB mRNA is located far from (-44 to -42) and too close to (-5 to -2) the initiation codon, respectively, and these sequences were not essential for translation. These results indicate that functional SD-like sequences are located around 10 nucleotides upstream from the translational start codon. Competition assays confirmed that a functional SD-like sequence interacts with the 3' terminus of chloroplast 16S rRNA.