Structural modeling showing the interaction between the tethered ligand and the LBS. The homology model for PAR4 in the activated state was generated by computational modeling. In this model, the tethered ligand is green, the LBS is red, and Gly48 and Thr153 are cyan. The TM4 and part of ECL2 are hidden on the homology model to provide a better view of the LBS.