Mediates the vitamin K-dependent carboxylation of glutamate residues to calcium-binding gamma-carboxyglutamate (Gla) residues with the concomitant conversion of the reduced hydroquinone form of vitamin K to vitamin K epoxide (PubMed:17073445). Catalyzes gamma-carboxylation of various proteins, such as blood coagulation factors (F2, F7, F9 and F10), osteocalcin (BGLAP) or matrix Gla protein (MGP) (PubMed:17073445).
