Energy-dependent efflux pump responsible for decreased drug accumulation in multi-drug-resistant cells. Probably uses a transmembrane proton gradient as the energy source. Causes the efflux of a variety of toxic substances, including such structurally diverse compounds as ethidium bromide, rhodamine and acridine dyes, tetraphenylphosphonium, puromycin, chloramphenicol, doxorubicin, and fluoroquinolone antibiotics. Belongs to the major facilitator superfamily. TCR/Tet family.