Structural insights into the exosite-mediated activation of Factor IX by Factor XIa using cryo-EM.
The first cryo-EM structures of FXIa in complex with its substrate, FIX, and activated FIX (FIXaβ) define the full FXIa:FIX interface providing a structural template for understanding the sequential activation of FIX and for developing a new class of selective allosteric antithrombotic agents.