Structural requirement in clostridium perfringens collagenase mRNA 5' leader sequence for translational induction through small RNA-mRNA base pairing.
Structural requirement in clostridium perfringens collagenase mRNA 5' leader sequence for translational induction through small RNA-mRNA base pairing.
复制标题
产气荚膜梭菌胶原酶 mRNA 5 前导序列通过小 RNA-mRNA 碱基配对进行翻译诱导的结构要求。
DOI：
10.1128/jb.00148-13
复制
发表时间：
2013
影响因子：
3.2
通讯作者：
Nobuhiko Nomura.
中科院分区：
文献类型：
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作者：
Nozomu Obana;Kouji Nakamura;Nobuhiko Nomura.
革兰氏阳性厌氧细菌产气荚膜梭菌对人类和动物具有致病性，并且其毒素的产生在指数期期间受到严格调节。我们最近发现，编码胶原酶（该生物体的主要毒素）的胶原酶转录本的5 '前导序列在小RNA VR-RNA的存在下被加工和稳定。primarycolA 5 ′-非翻译区（5′UTR）形成一个长茎环结构，包含一个内部凸起，并掩盖了自己的核糖体结合位点。我们发现VR-RNA在体内通过与colAmRNA的碱基配对直接调控大肠杆菌A的表达。然而，当内部凸起结构被点突变incolAmRNA关闭时，尽管存在VR-RNA，翻译仍停止。此外，在缺乏VR-RNA的情况下，一个破坏colA茎环结构的突变诱导了mRNA加工和ColA-FLAG翻译激活，表明colA 5 ′前导序列的茎环和内部凸起结构对VR-RNA的调节是重要的。另一方面，加工是ColA最大表达所必需的，但不是VR-RNA依赖性ColA调节所必需的。最后，在无VR-RNA的高温下，colA加工和翻译激活被诱导。这些结果表明，通过碱基配对抑制colA 5 ′前导结构是VR-RNA调节colA的主要作用，colA 5 ′前导结构可能是一种温度传感器。
The Gram-positive anaerobic bacterium Clostridium perfringens is pathogenic to humans and animals, and the production of its toxins is strictly regulated during the exponential phase. We recently found that the 5′ leader sequence of thecolAtranscript encoding collagenase, which is a major toxin of this organism, is processed and stabilized in the presence of the small RNA VR-RNA. The primarycolA5′-untranslated region (5′UTR) forms a long stem-loop structure containing an internal bulge and masks its own ribosomal binding site. Here we found that VR-RNA directly regulatescolAexpression through base pairing withcolAmRNAin vivo. However, when the internal bulge structure was closed by point mutations incolAmRNA, translation ceased despite the presence of VR-RNA. In addition, a mutation disrupting thecolAstem-loop structure induced mRNA processing and ColA-FLAG translational activation in the absence of VR-RNA, indicating that the stem-loop and internal bulge structure of thecolA5′ leader sequence is important for regulation by VR-RNA. On the other hand, processing was required for maximal ColA expression but was not essential for VR-RNA-dependentcolAregulation. Finally,colAprocessing and translational activation were induced at a high temperature without VR-RNA. These results suggest that inhibition of thecolA5′ leader structure through base pairing is the primary role of VR-RNA incolAregulation and that thecolA5′ leader structure is a possible thermosensor.