Figure 1. Overall structure of the glucosidase II α subunit.

(a) Schematic representation of Glc₃Man₉GlcNAc₂ showing the nomenclature of oligosaccharide residues and branches. Glucose residues trimmed by GII are shown in red. (b) Ribbon model of GIIα is represented with positions of N and C termini and individual domains. The individual domains are colored as the following: N-terminal domain (yellow), subdomain B1 (hot pink), β₈α₈ barrel domain (red), subdomain B2 (purple), subdomain B3 (orange), proximal C-terminal domain (blue), and distal C-terminal domain (green). The characteristic N-terminal segment is colored in cyan. The catalytic residues are shown as pale cyan sphere models.