Mechanisms of Non-Shine-Dalgarno Translation Initiation

项目总结 翻译起始的基本机制在大肠杆菌中被发现了40多年 那是以前的事了。尽管教科书上认为这种机制在所有细菌中普遍存在，但E。 Coli实际上高度适应利用Shine-Dalgarno序列进行翻译起始。 对不同物种的基因组数据的检查表明，只有不到一半的细菌 信息具有Shine-Dalgarno序列，将核糖体定位在起始密码子上。 事实上，许多致病细菌在大多数信息中都缺乏Shine-Dalgarno位点 在这些物种中，起始密码子选择的分子机制很大程度上是未知的。 Crescentus是目前研究非Shine-Dalgarno翻译的最佳模型系统 启动，因为它具有快速的加倍时间，广泛的遗传工具，以及较低的 起始于Shine-Dalgarno位点的基因(23.5%)，包括375个含有 8月5日。通过结合体外翻译试验和体内核糖体图谱实验，我们 寻求确定该生物体中非Shine-Dalgarno启动的重要方面。我们 我相信新月桂花翻译启蒙的许多特点将与 病原微生物的翻译起始途径，可能导致 确定新的抗生素靶标。

PROJECT SUMMARY The foundational mechanism of translation initiation was discovered in E. coli over 40 years ago. Despite the textbook perception that this mechanism is ubiquitous among all bacteria, E. coli is actually highly adapted to utilize Shine-Dalgarno sequences for translation initiation. Examination of genomic data across species reveals that fewer than half of all bacterial messages have Shine-Dalgarno sequences to position ribosomes at the initiation codon. Indeed, many pathogenic bacteria lack Shine-Dalgarno sites in most messages and the molecular mechanisms of start codon selection are largely unknown in these species. C. crescentus is currently the best model system to study non-Shine-Dalgarno translation initiation as it has a rapid doubling time, a broad array of genetic tools, and a low fraction of genes initiated at Shine-Dalgarno sites (23.5%), including 375 leaderless mRNAs containing a 5’ AUG. By combining in vitro translation assays and in vivo ribosome profiling experiments we seek to define the important aspects of non-Shine-Dalgarno initiation in this organism. We believe that many of the characteristics of C. crescentus translation initiation will be shared with the translation initiation pathways of pathogenic organisms, potentially leading to the identification of new antibiotic targets.