Crystal structure of CrSBPase. (A) Topology is displayed as cartoon with main chain colored from blue (amino-terminus) to red (carboxy-terminus). (B) Rotated view of A. by x-axis over -90°. (C) Close-up view of region A113SCAGTAC120 with disulfide bond shown in sticks. (D) Rotated view of C. by x-axis over -90°. (E) Putative active site residues inferred from alignment with FBPase bound to FBP (5l0a, human muscle fructose-1,6-bisphosphatase E69Q mutant in active R-state in complex with fructose-1,6-bisphosphate) are represented in sticks. Residue numbering is according to Chlamydomonas SBPase Uniprot entry P46284. (F) Surface representation in the B. orientation with putative active site residues colored in cyan. Water molecule 401 (W401) oxygen is represented as a red sphere. (G) Cysteines site chains are represented in spheres. (H) Threonines and serines side chains reported to be the target of phosphorylations are represented in spheres.