Required for MmpL3-dependent trehalose monomycolate (TMM) transport to the cell wall. Required for growth and cell elongation. Monomer (PubMed:31833106). Interacts (via N-terminus) with MmpL3; active trehalose monomycolate (TMM) biosynthesis is not required for the complex formation. Interacts with MSMEG_5308 (PubMed:31239378). Colocalizes with MmpL3 to the cell poles and septa. Trehalose monomycolate (TMM) synthesis is not required for localization to the poles or septa. The N-terminal domain (1-205) is necessary and sufficient for proper localization and function of this protein, and for its interaction with MmpL3. Knockdown of this gene leads to cessation of growth and shorter misshapen cells. Accummulation of trehalose monomycolate (TMM) and lack of trehalose dimycolate (TDM). Accumulates MSMEG_5308 protein.