Toovercome the difficultyof characterizing the structures of the extracellular loops (eLPs) ofGprotein-coupledreceptors (GPCRs) other than rhodopsin, we have explored a strategy to generate a three-dimensional structural model for a GPCR, the thromboxane A2 receptor. This three-dimen-sional structurewas completedby the assembly of theNMR structures of the computation-guided constrained peptides that mimicked the extracellular loops and connected to the conserved seven transmembrane domains.
