Part of a heme-iron acquisition system. Receives heme from the heme-binding protein Rv0203 and transports it into the mycobacterial cell. Contributes to virulence. Could also transport the mycolic acid-containing lipids monomeromycolyl diacylglycerol (MMDAG) and mycolate ester wax (WE) to the bacterial surface. Inactivation increases mouse survival. Mutants show growth patterns similar to the wild-type strain during the active growth phase, but they are attenuated for survival in the chronic stages of infection. Belongs to the resistance-nodulation-cell division (RND) (TC 2.A.6) family. MmpL subfamily.