FIGURE 4.

Substrate binding to N-loop and subdomain b2. Top (A) and side (B) views focusing on the N-loop and subdomain b2 bound to AC8 are shown as stereo diagrams. Amino acid residues and water molecules interacting with AC8 are represented by a stick model and red sphere, respectively. Two catalytic residues are indicated by asterisks. The dashed lines indicate hydrogen bonds. Color coding is similar to Fig. 3A. C, multiple sequence alignment at a region spanning Lys⁴⁹³ to Pro⁵⁰² was produced by MUSCLE (36). SOG, spinach α-glucosidase (O04893); BWG, buckwheat α-glucosidase (H. Mori, unpublished data); ONG1, rice α-glucosidase isozyme 1 (Q653V4); ONG2, rice α-glucosidase isozyme 2 (Q653V7); BAG, barley α-glucosidase (Q43763).