A site-specific factor interacts directly with its cognate RNA editing site in chloroplast transcripts
A site-specific factor interacts directly with its cognate RNA editing site in chloroplast transcripts
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DOI：
10.1073/pnas.0307163101
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发表时间：
2004-01-06
影响因子：
11.1
通讯作者：
Sugiura, M
中科院分区：
文献类型：
--
作者：
Miyamoto, T;Obokata, J;Sugiura, M
RNA编辑涉及多种遗传系统，并通过不同的机制发生。在高等植物叶绿体中，某些转录物的特定位点会发生C-到-U的转换。我们以前已经表明，psbE和petB mRNA编辑的位点特异性反式作用因子结合相应的顺式元件，其位于编辑位点上游5个核苷酸。在这里，我们报告说，通过使用标记在上游顺式元件的中心或在编辑位点的mRNA，位点特异性因子可以交联与核苷酸在这两个位置。编辑位点近端区域的核苷酸突变揭示了编辑活性和因子与编辑位点的交联效率之间的相关性，即使与上游顺式元件的交联不受影响：这些观察结果表明，位点特异性因子稳定地结合到上游顺式元件，而它与编辑位点的相互作用较弱。这一发现提出了一种有趣的可能性，即位点特异性因子参与叶绿体RNA编辑中的位点确定和C到U的转换。
RNA editing involves a variety of genetic systems and occurs by different mechanisms. In higher plant chloroplasts, specific sites of some transcripts are subject to C-to-U conversion. We have previously shown that site-specific trans-acting factors for psbE and petB mRNA editing bind corresponding cis-elements, which are located 5 nucleotides upstream from the editing site. Here we report that, by using mRNAs labeled either at the center of the upstream cis-element or at the editing site, the site-specific factors can be cross-linked with nucleotides at both positions. Mutations of nucleotides in the proximal region of the editing site revealed a correlation between editing activity and cross-linking efficiency of factors with the editing site, even though cross-linking with the upstream cis-element was unaffected: These observations suggest that the site-specific factor binds stably to the upstream cis-element, whereas it interacts weakly with the editing site. This finding raises the intriguing possibility that the site-specific factor is involved in both site-determination and C-to-U conversion in chloroplast RNA editing.