ID 3.4.21.27 DE Coagulation factor XIa. AN Plasma thromboplastin antecedent. CA Selective cleavage of Arg-|-Ala and Arg-|-Val bonds in factor IX to form CA factor IXa. CC -!- The proenzyme XI is activated by EC 3.4.21.38. CC -!- Belongs to peptidase family S1. PR PROSITE; PDOC00124; PR PROSITE; PDOC00376; DR Q5NTB3, FA11_BOVIN ; P03951, FA11_HUMAN ; Q91Y47, FA11_MOUSE ; //