Molecular Classification
Transporter, ABC transporter, MFS transporter, RND transporter, MATE transporter, SMR transporter, PACE transporter
Other Names
Multidrug efflux pumps, Drug efflux pumps, Efflux transporters
Disease Roles
Antibiotic resistanceInfection

Bacterial Efflux Pumps Overview

Bacterial efflux pumps are membrane-embedded protein complexes that actively transport a wide variety of substrates—including antibiotics, toxic compounds, metabolic byproducts, and signaling molecules—out of bacterial cells. This active export mechanism is a major contributor to antimicrobial resistance in bacteria by reducing the intracellular concentration of antibiotics below toxic levels. They are classified into several major families (ABC, MFS, RND, MATE, SMR, PACE), each utilizing different energy sources and having distinct substrate specificities. Efflux pumps play diverse roles beyond antibiotic resistance, including toxin removal, regulation of quorum sensing and biofilm formation, and modulation of membrane potential and redox state. Due to their significant contribution to multidrug resistance, they are considered important targets for novel antibacterial strategies. However, developing effective inhibitors remains challenging due to the structural diversity of these pumps.

Mechanism of Action

Active transport of substrates across the bacterial cell membrane, reducing intracellular concentration.

Biological Functions

Antibiotic resistance
Toxin removal
Metabolic waste removal
Quorum sensing regulation
Biofilm formation regulation
Regulation of membrane potential
Regulation of redox state

Disease Associations

Antibiotic resistance
Infection

Safety Considerations

  • Specificity of inhibitors (off-target effects)
  • Development of resistance to inhibitors
  • Structural diversity among pump types complicates inhibitor development

Interacting Drugs

Efflux pump inhibitors
ABI-PP
Antibiotics (substrates of efflux pumps)