Abstract
The urokinase receptor (uPAR) can recognize several ligands. The structural basis for this multiple ligand recognition by uPAR is unknown. This study reports the crystal structures of uPAR in complex with both urokinase (uPA) and vitronectin and reveal that uPA occupies the central cavity of the receptor, whereas vitronectin binds at the outer side of the receptor. These results provide a structural understanding of one receptor binding to two ligands.