Tags: Protein.
Coagulation factor XIII A chain is a protein that in humans is encoded by the F13A1 gene.This gene encodes the coagulation factor XIII A subunit. Coagulation factor XIII is the last zymogen to become activated in the blood coagulation cascade. Plasma factor XIII is a heterotetramer composed of 2 A subunits and 2 B subunits. The A subunits have catalytic function and the B subunits do not have enzymatic activity and may serve as plasma carrier molecules.