Figure 1.

Structures of ALG-2^ΔGF122 and ALG-2^F122A. Structures of (A) Ca²⁺-bound des3-23ALG-2^ΔGF122 (PDB ID 3AAJ) and (B) Zn²⁺-bound des3-20ALG-2^F122A (PDB ID 3AAK) are shown in magenta and orange, respectively, in ribbon representations, and EF-hand-coordinated calcium and zinc ions are shown in gray and light cyan spheres. The deleted site (Gly¹²¹Phe¹²²) and substituted site (F122A) are marked by an open arrowhead and closed arrowhead in (A) and (B), respectively. (C, D) The ALG-2 structures are compared with the previously resolved structures of wild-type ALG-2 of Ca²⁺-bound form (PDB ID 2ZN9) and Zn²⁺-bound form (PDB ID 2ZN8) by aligning at α-helix 4 (α4), and close-up views of segments from α5 to α6 are shown in ribbon representations. (C) The structures of Ca²⁺-bound des3-20ALG-2 and des3-23ALG-2^ΔGF122 are shown in green and magenta, respectively. The view in the left panel is rotated approximately 90° to view from the top as shown in the right panel. (D) The structures of Zn²⁺-bound ALG-2 (green) and des3-20ALG-2^F122A (orange) are presented similarly to (C).