Multidrug efflux pump. Confers resistance to tetraphenylphosphonium (TPP), erythromycin, ethidium bromide, acriflavine, safranin O and pyronin Y (By similarity). Belongs to the drug/metabolite transporter (DMT) superfamily. Small multidrug resistance (SMR) (TC 2.A.7.1) family. Mmr subfamily.