The substrate specificity of tripartite efflux systems of Pseudomonas aeruginosa is determined by the RND component

Biochem Biophys Res Commun. 2002 Nov 29;299(2):247-51. doi: 10.1016/s0006-291x(02)02626-8.


The tripartite efflux systems MexAB-OprM and MexCD-OprJ of Pseudomonas aeruginosa each display characteristic substrate specificity against a variety of antimicrobial agents. The chimeric efflux system MexC-MexB-OprJ/DeltaMexD constructed by exchange of MexD with MexB endowed the recombinant host the same resistance profile as MexAB-OprM rather than MexCD-OprJ. The change of substrate specificity was shown to be due to extrusion from the chimeric efflux system by cellular accumulation experiments using tetracycline, erythromycin, and ethidium bromide. Thus, we conclude that MexB and MexD are primary components of the efflux system responsible for sorting extrusion substrates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / metabolism*
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Biological Transport
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Drug Resistance, Bacterial
  • Erythromycin / metabolism
  • Ethidium / metabolism
  • Kinetics
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Membrane Transport Proteins / metabolism
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Substrate Specificity
  • Tetracycline / metabolism


  • Anti-Bacterial Agents
  • Bacterial Outer Membrane Proteins
  • Carrier Proteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • MexB protein, Pseudomonas aeruginosa
  • MexD protein, Pseudomonas aeruginosa
  • OprM protein, Pseudomonas aeruginosa
  • Recombinant Fusion Proteins
  • Erythromycin
  • Ethidium
  • Tetracycline