Global resource allocation by bacteria during carbon starvation.

Survival through periods of starvation is crucial for bacterial fitness. Synthesis of “stress response” proteins during starvation is essential to maintain long-term survival. However, little is known about how protein synthesis is maintained during starvation. Here, we report the discovery of a starvation-triggered global protein degradation system that fuels gene expression by providing both amino acids and energy for protein synthesis during glucose starvation in E. coli. The cost of protein synthesis is determined quantitatively in terms of the required protein degradation flux, and the regulatory strategy adopted by E. coli to ensure coordination between synthesis and degradation is established by measuring responses to various perturbations.