Collaborative Research: The Role of Quality Control in Microbial Translation

为了正常运作，细胞必须在处理遗传信息转移的所有过程中保持一定程度的保真度。翻译是遗传信息从核酸序列转移到蛋白质的氨基酸序列的过程。翻译的保真度主要取决于两个方面：核糖体选择氨基酰-tRNA的准确性和氨基酰-tRNA合成酶(AARS)在氨酰化反应过程中合成同源氨基酸/tRNA对的准确性。AARs通过将tRNA与相应的氨基酸配对来定义遗传密码。准确的氨基酰基-tRNA合成通常需要许多AARs固有的额外编辑活动。编辑显著减少了体外合成氨基酰tRNA过程中的错误频率，尽管反应机制和编辑对活细胞的影响的许多细节仍不清楚。本项目的目标是利用苯丙氨酰-tRNA合成酶(PHERS)作为模型系统来阐明编辑的分子机制，并研究编辑在细胞中的生理作用。拟议活动产生的更广泛影响将是为本科生和研究生，包括历史上代表性不足的少数民族成员，提供综合实验室研究和培训方案，并为初中和高中教师及其学生提供实验室培训和教育经验。

To function properly the cell must maintain a certain level of fidelity in all processes dealing with the transfer of genetic information. Translation is the process by which genetic information is transferred from a nucleic acid sequence into the amino acid sequence of a protein. The fidelity of translation is determined at two major points: the accuracy of aminoacyl-tRNA selection by the ribosomes and synthesis of cognate amino acid/tRNA pairs by aminoacyl-tRNA synthetases (aaRS) in the course of the aminoacylation reaction. The aaRSs define the genetic code by pairing tRNAs with the corresponding amino acids. Accurate aminoacyl-tRNA synthesis often requires an additional editing activity intrinsic to many aaRSs. Editing significantly decreases the frequency of mistakes during aminoacyl-tRNA synthesis in vitro, although many details of the reaction mechanism and the impact of editing on the living cell remain unclear. The goals of this project are to use phenylalanyl-tRNA synthetase (PheRS) as a model system to clarify the molecular mechanisms of editing, and to investigate the physiological role of editing in the cell. The broader impacts resulting from the proposed activity will be to provide integrated laboratory research and training programs for both undergraduate and graduate students including members of historically underrepresented minorities, and to provide laboratory training and education experiences for middle and high school teachers and their students.