Kruse Elisabeth, Voigt Christin, Leeder W-Matthias, Göringer H Ulrich
Darmstadt University of Technology, Darmstadt, Germany.
Biochim Biophys Acta. 2013 Aug;1829(8):835-41. doi: 10.1016/j.bbagrm.2013.04.003. Epub 2013 Apr 13.
Mitochondrial pre-messenger RNAs in kinetoplastid protozoa such as the disease-causing African trypanosomes are substrates of a unique RNA editing reaction. The process is characterized by the site-specific insertion and deletion of exclusively U nucleotides and converts nonfunctional pre-mRNAs into translatable transcripts. Similar to other RNA-based metabolic pathways, RNA editing is catalyzed by a macromolecular protein complex, the editosome. Editosomes provide a reactive surface for the individual steps of the catalytic cycle and involve as key players a specific class of small, non-coding RNAs termed guide (g)RNAs. gRNAs basepair proximal to an editing site and act as quasi templates in the U-insertion/deletion reaction. Next to the editosome several accessory proteins and complexes have been identified, which contribute to different steps of the reaction. This includes matchmaking-type RNA/RNA annealing factors as well as RNA helicases of the archetypical DEAD- and DExH/D-box families. Here we summarize the current structural, genetic and biochemical knowledge of the two characterized "editing RNA helicases" and provide an outlook onto dynamic processes within the editing reaction cycle. This article is part of a Special Issue entitled: The Biology of RNA helicases - Modulation for life.
在诸如致病的非洲锥虫等动基体原生动物中，线粒体前体信使RNA是一种独特的RNA编辑反应的底物。该过程的特点是仅在特定位点插入和删除U核苷酸，并将无功能的前体mRNA转化为可翻译的转录本。与其他基于RNA的代谢途径类似，RNA编辑由一种大分子蛋白质复合物——编辑体催化。编辑体为催化循环的各个步骤提供了一个反应表面，并且作为关键参与者涉及一类特定的小的非编码RNA，称为引导（g）RNA。gRNA在编辑位点附近形成碱基对，并在U插入/删除反应中充当准模板。除了编辑体外，还鉴定出了几种辅助蛋白和复合物，它们参与反应的不同步骤。这包括匹配型RNA/RNA退火因子以及典型的DEAD-和DExH/D-box家族的RNA解旋酶。在这里，我们总结了两种已表征的“编辑RNA解旋酶”的当前结构、遗传和生化知识，并对编辑反应循环中的动态过程进行了展望。本文是名为：RNA解旋酶的生物学——生命的调控 的特刊的一部分。
