Fig. 3: The cryo-EM structure of substrate-bound MaPimE.
From: Mechanistic studies of mycobacterial glycolipid biosynthesis by the mannosyltransferase PimE
a, b Cryo-EM density for the product-bound complex of MaPimE with Ac1PIM5 (product) and PP (by-product), viewed parallel to the membrane plane. Fab-E6 binds to the same cytoplasmic domain of MaPimE as observed in the apo structure. c–e Ribbon representation for the product-bound structure of PimE (white) bound with PP (blue) and Ac1PIM5 (magenta) shown in different orientations. PP and Ac1PIM5 adopt a curved shape, with their polar head groups projecting into the hydrophilic center of the substrate-binding cavity. f–h A focused view of the region where PP and Ac1PIM5 bind. PP and Ac1PIM5 adopt a curved shape. The polyprenyl chain of PP points towards the hydrophobic TM domain groove composed of TM helices 6 and 9, while Ac1PIM5 is surrounded by PL1, JM1, and JM4, with its acyl chains likely extending toward the TM region near TM helix 3.
