Might be involved in transporting short diacylated glycolipids to the cell outer membrane (By similarity). Overexpression induces expression of sensor protein kdpD gene at low K(+) concentrations (0 and 250 uM, tested in M.smegatis). May interact with sensor protein KdpD. Forms a U-shaped beta-half-barrel with a small hydrophobic cavity which is large enough to hold a single diacylated glycolipid molecule. Modified by Lgt on Cys-39 with an S-linked diacylglycerol with a mixture of C16, C18 and C19 fatty acids (palmitic, stearic and tuberculostearic acid respectively), signal peptide is removed by LspA, modified by Lnt with an amide-linked mixture of C16 and C19 fatty acids, expressed in M.bovis (PubMed:24093492). Hexose glycosylated in N-terminus between residues 39 and 63 (PubMed:24093492). Expressed in M.bovis, lipidated and glycosylated. Belongs to the LppX/LprAFG lipoprotein family.