Maturation of the proplasmepsin zymogen

Upon enzymatic cleavage, the N-terminal of the inactive proenzyme (pink) relocates and forms a β-strand; this motion is coupled to the closure of the binding site. The N-terminal residues Ser1 and Ser2 and the active site residues Asp34 and Asp214 are shown in a ball and stick representation. Note the contact formed between the N-terminus and the active site during the maturation process.