Operon mRNAs are organized into ORF-centric structures that predict translation efficiency
Operon mRNAs are organized into ORF-centric structures that predict translation efficiency
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DOI：
10.7554/elife.22037
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发表时间：
2017-01-31
期刊：
影响因子：
7.7
通讯作者：
Gross, Carol A.
中科院分区：
文献类型：
--
作者：
Burkhardt, David H.;Rouskin, Silvi;Gross, Carol A.
细菌mRNAs被组织成操纵子，在单个多顺反子mRNA中由离散的开放阅读框架(ORF)组成。信使核糖核酸上的单个开放阅读框有不同的翻译，其速率差异高达100倍。对控制差异翻译的信号知之甚少。我们的全基因组mRNA二级结构分析表明，操纵子mRNAs由ORF范围内的二级结构单元组成，这些单元在ORF边界上变化，使得同一RNA分子上相邻的ORF在结构上是不同的。ORF的翻译率与其体内的mRNA结构密切相关，尽管相关程度有所降低，但与翻译被抑制时的结构和体外折叠的mRNA的相关性仍然存在。这些数据表明，固有的ORF mRNA结构编码了翻译效率的大致蓝图。然后，在一个自我加强的循环中，通过翻译放大这种结构，以提供最终指定每个ORF的翻译的结构。
Bacterial mRNAs are organized into operons consisting of discrete open reading frames (ORFs) in a single polycistronic mRNA. Individual ORFs on the mRNA are differentially translated, with rates varying as much as 100-fold. The signals controlling differential translation are poorly understood. Our genome-wide mRNA secondary structure analysis indicated that operonic mRNAs are comprised of ORF-wide units of secondary structure that vary across ORF boundaries such that adjacent ORFs on the same mRNA molecule are structurally distinct. ORF translation rate is strongly correlated with its mRNA structure in vivo, and correlation persists, albeit in a reduced form, with its structure when translation is inhibited and with that of in vitro refolded mRNA. These data suggest that intrinsic ORF mRNA structure encodes a rough blueprint for translation efficiency. This structure is then amplified by translation, in a self-reinforcing loop, to provide the structure that ultimately specifies the translation of each ORF.