A stress-limiting, self-regulatory protein production system. (A) Schematic presentation of recombinant protein production coupled to a negative feedback mechanism in an E. coli host cell. (B) Experimental setup for the implementation of a negative feedback mechanism into a protein production system. A modified pET23(+) vector harboring a TetR binding site (pET23b_TetO) is used for recombinant protein (rProtein) expression. On a 2nd plasmid (pNF_TetR), TetR is expressed under the control of the stress sensitive PIbpAB promoter.