A tuneable genetic switch for tight control of tac promoters in Escherichia coli boosts expression of synthetic injectisomes.

ABSTRACT: Biosafety of engineered bacteria as living therapeutics requires a tight regulation to control the specific delivery of protein effectors, maintaining minimum leakiness in the uninduced (OFF) state and efficient expression in the induced (ON) state. Here, we report a three repressors (3R) genetic circuit that tightly regulates the expression of multiple tac promoters (Ptac) integrated in the chromosome of E. coli and drives the expression of a complex type III secretion system injectisome for therapeutic protein delivery. The 3R genetic switch is based on the tetracycline repressor (TetR), the non-inducible lambda repressor cI (ind-) and a mutant lac repressor (LacI^W220F ) with higher activity. The 3R switch was optimized with different protein translation and degradation signal

SUBMITTER: Asensio-Calavia A 

PROVIDER: S-EPMC10832536 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature