Real time determination of bacterial in vivo ribosome translation elongation speed based on LacZα complementation system

Abstract

Bacterial growth significantly depends on protein synthesis catalyzed by ribosome. Ribosome translation elongation speed is a key factor determining the bacterial protein synthesis rate. However, existing methods for determining translation elongation speed have limited applications. Here we developed a simple and convenient method for measuring bacterial translation elongation speed based on LacZα complementation system. It enables the measurement of in vivo translation elongation speed of different individual genes. Tests related to ribosome translation elongation speed under various growth perturbations including different nutrient conditions, low temperature, a low-speed ribosome mutant, and fusidic acid treatment, were performed to quantitatively validate this method. Using this approach, we further found that nutrient starvation caused a remarkable slow-down of ribosome translation of Escherichia coli (E. coli). We also studied the dynamic change of translation elongation speed during the process of nutrient up-shift. This method will boost the quantitative understanding of bacterial ribosome translation capacity and growth.