Crystal structure of the unoccupied murine urokinase‐type plasminogen activator receptor ( uPAR ) reveals a tightly packed DII–DIII unit

The urokinase‐type plasminogen activator receptor ( uPAR ) is a cell surface receptor that is capable of binding to a range of extracellular proteins and triggering a series of proteolytic and signaling events. Previous structural studies of uPAR with its ligands uPA and vitronectin revealed that its three domains ( DI , DII , and DIII ) form a large hydrophobic cavity to accommodate uPA . In the present study, the structure of unoccupied murine uPAR (mu PAR ) is determined. The structure of DII and DIII of mu PAR is well defined and forms a compact globular unit, while DI could not be traced. Molecular dynamic simulations further confirm the rigid binding interface between DII and DIII . This study shows overall structural flexibility of uPAR in the absence of uPA .