Mycobacterial lipoprotein LprG can bind triacylated phospholipids such as phosphatidylinositol mannoside (PIM) and lipoarabinomannan (LAM). LprG is in an operon reported with a integral membrane transporter. LprG binds to PIM and LAM and transports them to the cell surface of Mycobacterium tuberculosis. [1]
Function
Macromolecule LprG biochemical function is binding and transportation. For binding it interacts selectively and noncovalently with glycerophospholipids and phosphorylated derivatives. As for transportation LprG binds triacylglyceride (TAG) in a large hydrophobic cleft and transfers TAG from donor to acceptor membranes. [1]
Disease
Tuberculosis is an infectious disease that is the second leading cause of death worldwide. Mycobacterium tuberculosis is an intracellular bacterial pathogen in infected macrophages. It contributes to antibiotic resistance and plays a critical role in regulating host response and aid survival of pathogen. LprG determines the distribution components of mycobacterium tuberculosis cell envelope. [1]
Structural highlights
LprG (4ZRA) consists of two chains A and C containing alpha-beta folds. contains 10 anti-parallel ß-sheets by 6 α-helices which defines the central cavity entrance. The is located at the entrance and has a conserved orientation.There are three acyl chains bound within the cavity sn1, sn2, and which form interactions with hydrophobic residue side chains within the cavity. The third acyl chain is exposed to the solvent and the other two (sn1 and sn2) are not shown. At the cavity entrance the hydophilic glyceryl interacts with . The sn3 chain is near two grooves that contain Ile, Leu, Val, and Phe. These grooves could facilitate the binding of TAG with other longer acyl chains.[1]
