Computational modeling of the OPRM1 homodimer interface. (a) This figure illustrates the position of cholesterol relative to the palmitoyl and the OPRM1 TMH bundle. The view is from lipid looking toward TMH4 (yellow). The OPRM1 model is displayed in molecular surface view, with cholesterol (green) and palmitoyl (orange) contoured at their VDW radii. TMH3 and TMH5 are in orange and cyan, respectively. (b) This figure illustrates an extracellular view of protomers A and B forming the OPRM1 homodimer TMH4 interface. Residues that form the interface (N4.41, I4.44, C4.48, I4.51, A4.55, and P4.59) are contoured at their VDW radii and colored magenta. Also contoured at their VDW radii are the palmitoyls (orange) and cholesterols (green). In this arrangement, cholesterols associated with one protomer also interact with the opposite protomer.
Zheng et al. BMC Cell Biology 2012 13:6 doi:10.1186/1471-2121-13-6