Fig. 3: Mechanism of catalysis and product release.

a Comparison of the cryo-EM density map of the phosphate-binding pocket between G6PC1^APO and G6PC1^Pi. G6PC1^APO is colored light blue and shown on the left; G6PC1^Pi is colored light pink and shown on the right. Phosphate is depicted in orange. b Slice view of the electrostatic surface of G6PC1^Pi. Phosphate is represented as spheres. The distance of phosphate from the cavity orifice is labeled. c Detailed interactions between G6PC1^Pi and phosphate. The interacting residues are shown as sticks. Phosphate is shown in a ball-and-stick representation. Phosphate and interacting residues are shown as opaque; the G6PC1 backbone are rendered translucent. Salt bridges are shown as black dashed lines. The non-existed interaction between S117 and the phosphate is depicted as a red dashed line and labeled. d Overall structural comparison between G6PC1^G6P and G6PC1^Pi, which are colored pale yellow and light pink, respectively. Phosphate is represented as spheres. e Alignment of interactions in the phosphate-binding site between G6PC1^G6P and G6PC1^Pi. f Comparison of interactions in the glucose moiety-binding site between G6PC1^G6P and G6PC1^Pi. g Salt bridges between G6P and E110, R170 and R83 of G6PC1^Pi. Side chains are shown as sticks, and electrostatic interactions are represented by black dashed lines. h Salt bridges between G6P and E110, R170 and R83 of G6PC1^APO and G6PC1^G6P. The non-existed salt bridges are shown as red dashed lines and labeled. i, j Structural alignment between G6PC1^APO (light blue) and G6PC1^Pi (light pink), shown in side view (i) and top-down view (j). Phosphate is represented as spheres. k Comparison of interactions in phosphate-binding site between G6PC1^APO and G6PC1^Pi.