Fig. 2.

Schematic representation of the primary structure of the proprotein convertases (PCs). The primary structures and domains of the nine PCs including the two alternative spliced forms of PC5/6 PC5/6A and PC5/6B are shown. The signal peptide, the prosegment, and the catalytic domain with typical catalytic triad residues Asp, His, and Ser are common to all the PCs. The other domains and the number of the amino acid (aa) for each proprotein convertase (PC) are also indicated.