FIGURE 3.

Binding of acarviosyl-maltooligosaccharides to SBG. A, overall structure of SBG bound with AC8 (purple stick). The active site pocket comprises the N-loop protruding from the N-terminal domain (pink), the catalytic (β/α)₈-barrel domain (light orange), and subdomains b1 (orange) and b2 (yellow), which are inserted into the catalytic domain. The proximal and distal C-terminal domains (light green and light blue) are not directly involved in substrate binding. N-Glycans (green stick) were attached to Asn⁴⁰⁴, Asn⁷²⁸, and Asn⁸²³. B, the σ_A-weighted composite omit maps (2F_o − F_c) are drawn around AC5-AC8 molecules and contoured at 1σ. C, superimposition of AC4 (cyan), AC5 (green), AC6 (magenta), AC7 (yellow), and AC8 (purple) bound to SBG.