Vitamin k is responsible for the carboxylation of which amino acid in the clotting factors: (A) Aspaate, (B) Glutamate, (C) Proline, (D) Lysine
Answer is B. Ref Robbins 8/e p 119;9/e p119 The vitamin K-dependent carboxylase carries out the posttranslational modification of specific glutamate residues in proteins togamma-carboxy glutamic acid (Gla) in the presence of reduced vitamin K, molecular oxygen, and carbon dioxide.