FUNCTION Initiates the extrinsic pathway of blood coagulation. Serine protease that circulates in the blood in a zymogen form. Factor VII is converted to factor VIIa by factor Xa, factor XIIa, factor IXa, or thrombin by minor proteolysis. In the presence of tissue factor and calcium ions, factor VIIa then converts factor X to factor Xa by limited proteolysis. Factor VIIa also converts factor IX to factor IXa in the presence of tissue factor and calcium (By similarity).CATALYTIC ACTIVITY Selective cleavage of Arg-|-Ile bond in factor X to form factor Xa.SUBUNIT Heterodimer of a light chain and a heavy chain linked by a disulfide bond.SUBCELLULAR LOCATION Plasma and liver.INDUCTION Expression in the liver and plasma oscillates in a circadian manner.PTM The vitamin K-dependent, enzymatic carboxylation of some glutamate residues allows the modified protein to bind calcium.PTM The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.PTM Can be either O-glucosylated or O-xylosylated at Ser-93 by POGLUT1.SIMILARITY Belongs to the peptidase S1 family.