Required for the biosynthesis of polyacyltrehalose (PAT) and the transport of diacyltrehalose (DAT) and possibly PAT to the cell surface. Deletion mutant accumulates important amounts of DAT and is devoid of PAT. DAT only accumulates inside the cells and is not exported to the cell surface. Belongs to the resistance-nodulation-cell division (RND) (TC 2.A.6) family. MmpL subfamily.