Figure 3. Synthetic systems engineering strategy to rewire the nitrogen regulatory network and enable regulon-wide transcription control.

NtrC, the central nitrogen stress regulator, directly regulates more than 20 operons of the nitrogen stress-response network. The engineered ZraR–NtrC chimaera can therefore specifically regulate NtrC-targeting promoters under zinc stress signal to control the nitrogen stress transcriptional regulon in E. coli ΔglnG.