Fig. 1.

Overall structure of the class I mutant, G6PD^P396L. (A) Overall structure of the dimer G6PD^P396L. Two G6PD molecules and the catalytic NADP⁺ are shown in blue, light blue, and orange, respectively. The catalytic NADP⁺-binding site is shown in close-up view on the Right. The Fo-DFc map for the catalytic NADP⁺ is contoured at 3.0σ level. (B) Space filling model of the dimer G6PD^P396L. (C) Space filling model of the dimer G6PD^WT. (D) Superimposition of the dimer G6PD^P396L and G6PD^WT. Distance between Cα-carbon atoms of E93 residues in the G6PD^P396L and G6PD^WT structures are shown. (E and F) The thermal denaturation curves of the G6PD^P396L and G6PD^WT with or without NADP⁺ (Top). The error bars indicate the SDs (n = 4). Bottom shows the derivative values of the thermal denaturation curves on the Top. (G) Crystal structure of G6PD^P396L dimer is superimposed with the cryo-EM map of G6PD^P396L. The G6PD^P396L dimer on the Left is rotated by 90° on the Right. (H) Crystal structure of the G6PD^WT tetramer (PDB ID: 6E08) is superimposed with the cryo-EM map of G6PD^WT. The cryo-EM map of the Left half on the Left (enclosed with a dashed rectangle) is extracted and rotated by 90°. The crystal structure of the G6PD^WT dimer (PDB ID: 6E08) is superimposed with the cryo-EM map on the Right.