Model of hAGRP (87-132)-mMC4R complex
(A) mMC4R receptor model (TM helical bundle and extracellular domain) viewed along the helical axes from the extracellular end. The TM helices are colored green, and extracellular loops are colored yellow. Side chains of Asp103 and Asp105 acidic residues in EL1 are highlighted. (B) Structural model of the hAGRP-(87-132)-mMC4R structure, visualized using CAChe V5.0, showing that the protein interacts with both the extracellular loops and an intramembrane binding site. AGRP is colored by atom type: C, black; O, red; N, blue; H, white; S, yellow. TM helical domains are the following: 1, red; 2, yellow; 3, green; 4, purple; 5, cyan; 6, orange; 7, black. Loops are colored blue. (C) Illustration of the hydrophilic binding pocket for AGRP(87-132) in mMC4R. The receptor and ligand are depicted as ribbons in green and red, respectively. The side chains of the important residues involved in the ionic bridge are highlighted and labeled. (D) Illustration of the hydrophobic binding pocket for AGRP(87-132) in mMC4R. The receptor and ligand are depicted as ribbons in green and red, respectively. The side chains of the important residues involved in the aromatic interaction are highlighted and labeled.