Non-conventional translation initiation in bacteria

细菌中的非常规翻译起始

• 批准号: 171579282
• 负责人: Professor Dr. Jörg Soppa
• 金额: --
• 依托单位: Arbeitskreis Biologie und Genetik von Prokaryonten
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/171579282?language=en
• 关键词: Non; conventional; translation; initiation; bacteria

The conventional pathway of translation initiation in prokaryotes relies on the interaction of a Shine Dalgarno (SD) motif with the 3’-end of the 16S rRNA. Recently we could show that translation initiation in haloarchaea is predominated by two non-conventional mechanisms (leaderless transcripts and SD-less transcripts). We have now extended the characterization of translation initiation to Escherichia coli. We could show that SD-less transcripts exist also in E. coli, indicating that non-conventional mechanisms for translation initiation are also used by bacteria. We will use translatome analyses for a global characterization of transcripts with non-average translational efficiencies under stress conditions or kasugamycin treatment. A dual reporter gene system will be used to quantify relative translational efficiencies of the conventional and non-conventional mechanisms under various conditions, and the role of cis-acting elements will be analyzed by mutagenesis. Initiation complexes will be isolated and by using ultrasoft mass spectrometry and proteomics it will be revealed whether specialized complexes exist under different conditions or on non-conventional transcripts (similar to the recently identified specialized 61S ribosomes).

在原核生物中，传统的翻译起始途径依赖于Shine Dalgarno(SD)基序与16S rRNA的3‘端的相互作用。最近我们发现，在盐生古生菌中，翻译的启动主要由两种非常规机制(无领导转录本和无SD转录本)主导。我们现在已经将翻译起始的特征扩展到了大肠杆菌。我们可以证明在大肠杆菌中也存在无SD的转录本，这表明细菌也使用非传统的翻译启动机制。我们将使用翻译组分析，对在胁迫条件或卡苏霉素处理下具有非平均翻译效率的转录本进行全球表征。将使用双报告基因系统来量化常规和非常规机制在不同条件下的相对翻译效率，并将通过突变来分析顺式作用元件的作用。起始复合体将被分离，并通过使用超软质谱学和蛋白质组学，将揭示是否在不同条件下或在非常规转录本上存在专门化复合体(类似于最近发现的专门化61S核糖体)。