细菌核糖体翻译延伸速率测定方法的改进

定量理解不同种类细菌之间生长能力的巨大差异是微生物学的重大研究难题。对于细菌来说，其代谢与能量资源主要用于蛋白质合成。因此蛋白质合成在细菌生长中处于核心环节。核糖体负责合成蛋白质。蛋白质的合成速率取决于两个重要定量指标即核糖体的含量以及单位核糖体的翻译延伸速率。核糖体含量可以通过测定RNA/protein比值得出，然而，测定细菌核糖体翻译延伸速率的传统方法具有较大局限性，因此这一重要参数在其它种类细菌中鲜有报道。在近期的工作中,我们建立了一种基于β-半乳糖苷酶阿尔法互补系统的方法来测定细菌翻译延伸速率。该方法简单快捷并且定量性较好，但其目前主要适用于大肠杆菌的相关研究。本研究旨在改进该方法，并结合绿色荧光蛋白报告系统，建立可以测定其它不同种类细菌核糖体翻译延伸速率的普适性方法。新方法将为理解不同细菌生长能力差异的内在机制提供有力的技术性支撑。

Quantitatively understanding the great differences of growth capacity among different bacteria species is one grand challenge in microbiology. Bacteria cells devote most metabolic and energy resources to protein synthesis. Protein synthesis therefore plays a central role in bacterial growth. Ribosome is engaged in protein synthesis. In vivo protein translation capacity depends on two key quantitative parameters, ribosome content and ribosome translation elongation rate. Ribosome content can be obtained by measuring RNA/protein ratio. However, traditional methods for measuring translation elongation rate have limited applications, thus it has been rarely reported of this parameter for different kinds of bacteria species. In our recent work, we developed a method of determining bacteria translation elongation rate based on the β-galactosidase alpha complementation system in E. coli. The method is rapid and convenient with excellent quantitative properties. However, its application is still mainly limited to E. coli. This research plan aims to improve this method and combine the green fluorescent protein reporter system for establishing a general method of measuring the translation elongation rate of other bacteria species. The new method will provide powerful technical support for understanding the intrinsic mechanism underlying the varied growth capacity among various bacteria species.