Tunable protein degradation in bacteria

Tunable control of protein degradation in bacteria would provide a powerful research tool. We use components of the Mesoplasma florum tmRNA system to create a synthetic degradation system that provides both independent control of the steady-state protein level and inducible degradation of targeted proteins in Escherichia coli. We demonstrate application of this system in synthetic circuit development and control of core bacterial processes and antibacterial targets, and transfer the system to Lactococcus lactis to establish its broad functionality in bacteria. We create a 238-member library of tagged essential proteins in E. coli that can serve as both a research tool to study essential gene function and an applied system for antibiotic discovery. Our synthetic protein degradation system is modular, does not require disruption of host systems, and can be transferred to diverse bacteria with minimal modification.