Cryo‐EM structures of coagulation factors

A State of the Art lecture titled “Cryo‐EM structures of coagulation factors” was presented at the ISTH Congress in 2022. Cryogenic electron microscopy (cryo‐EM) is a revolutionary technique capable of solving the structure of high molecular weight proteins and their complexes, unlike nuclear magnetic resonance (NMR), and under conditions not biased by crystal contacts, unlike X‐ray crystallography. These features are particularly relevant to the analysis of coagulation factors that are too big for NMR and often recalcitrant to X‐ray investigation. Using cryo‐EM, we have solved the structures of coagulation factors V and Va, prothrombinase on nanodiscs, and the prothrombin‐prothrombinase complex. These structures have advanced basic knowledge in the field of thrombosis and hemostasis, especially on the function of factor V and the molecular mechanism for prothrombin activation, and set the stage for exciting new lines of investigation. Finally, we summarize relevant new data on this topic presented during the 2022 ISTH Congress.