Probably helps membrane protein MRA_1419 (P55) transport triacylglycerides (TAG) across the inner cell membrane into the periplasm and probably ultimately to the outer membrane. TAG probably regulates lipid metabolism and growth regulation. Binds di- and triacylated phosphatidyl-myo-inositol mannosides (PIMs), and glycolipid lipoglycan modulins lipoarabinomannan (LAM) and lipomannan (LM) (PubMed:25356793). Probably facilitates recognition of glycolipids by TLR2. Required for activity of drug efflux transporter MRA_1419. Required, probably with MRA_1419, for normal surface localization of LAM. Constitutes a host TLR2 agonist (toll-like receptor). Forms a U-shaped beta-half-barrel with a small hydrophobic cavity able to hold a triacylated lipid or triacylglyceride. Modified by Lgt on Cys-27 with an S-linked diacylglyceral, signal peptide is removed by LspA, Cys-27 is further modifed with a fatty acid on its amino group by Lnt yielding a triacylated protein (By similarity). Single deletion mutant (probably without MRA_1419) has decreased surface-exposed glycolipid lipoarabinomannan (LAM), although cellular LAM, LM and PIM content is normal (PubMed:25356793). Bacterial LAM blocks host cell phagosome-lysosome fusion and is one way in which M.tuberculosis evades the host immune system. Triacylglycerides accumulate in lipid droplets in the cytoplasm of M.tuberculosis stationary phase and dormant bacteria, and are used as an energy source during starvation. Belongs to the LppX/LprAFG lipoprotein family.