Maltose-binding Protein Improving the Crystallizability of C2 Domain of Human Coagulation Factor V

Human coagulation Factor V(FV), together with Factor Xa, assembles to prothrombinase complex on activated cell surface, which converts prothrombin into thrombin, leading to fibrin deposition. The C2 domain of FV is believed to be a primary anchor for the assembly of pro- thrombinase on the cell surface, and was proposed as a target to intervene with pathological thrombotic events. We report here the crystal structure of the C2 domain of FV fused to maltose-binding protein(MBP). The fusion tag of MBP is critical to generate the crystal for this study. There is no strong interaction between MBP and FVC2. The overall structure of FVC2 is similar to the previous FVC2 structures, suggesting the MBP fusion does not perturb the molecular structure of FVC2. This crystal form of FVC2 can be used for future study of molecular interaction between FVC2 and its inhibitors.