CpxR Escherichia coli CpxR Ecol_CpxR antibiotic_resistance ARO:3004055 The Escherichia coli CpxR/CpxA system responds to general periplasmic stress and has been used as a model two-component system for transcription regulation in bacteria. CpxR/CpxA system facilitates Salmonella and E. coli resistance to cationic antimicrobial peptides.The CpxR/CpxA system can activate transcription of marRAB operon, thus facilitating multidrug-resistant regulator to enhance expression of TolC-dependent tripartite multidrug transporters.