A DNA enzyme that mimics the first step of RNA splicing
A DNA enzyme that mimics the first step of RNA splicing
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DOI：
10.1038/nsmb727
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发表时间：
2004-03-01
影响因子：
16.8
通讯作者：
Silverman, SK
中科院分区：
文献类型：
--
作者：
Coppins, RL;Silverman, SK
我们已经发现了一种人工DNA酶，它模仿了RNA剪接的第一步。采用体外筛选法鉴定连接RNA的DNA酶。其中一种新的DNA酶通过特异性识别未配对的内部腺苷并促进其2'-羟基对5'-三磷酸的攻击来进行剪接相关的催化。该反应形成2,5 '支链RNA，类似于体内RNA剪接的第一步，其中核酶通过形成分支中间体来切割自身。与天然核酶不同，新的DNA酶没有2'-羟基来帮助催化机制。我们的发现有两个重要的含义。首先，分支位点腺苷反应性似乎在机制上受到核酸酶的青睐。其次，羟基不是进行生物相关催化的核酸酶的必需组分。
We have discovered an artificial DNA enzyme that mimics the first step of RNA splicing. In vitro selection was used to identify DNA enzymes that ligate RNA. One of the new DNA enzymes carries out splicing-related catalysis by specifically recognizing an unpaired internal adenosine and facilitating attack of its 2'-hydroxyl onto a 5'-triphosphate. This reaction forms 2, 5'-branched RNA and is analogous to the first step of in vivo RNA splicing, in which a ribozyme cleaves itself with formation of a branched intermediate. Unlike a natural ribozyme, the new DNA enzyme has no 2'-hydroxyl groups to aid in the catalytic mechanism. Our finding has two important implications. First, branch-site adenosine reactivity seems to be mechanistically favored by nucleic acid enzymes. Second, hydroxyl groups are not obligatory components of nucleic acid enzymes that carry out biologically related catalysis.