Wide-eye stereo view of the GlpX active site. A, FBP bound
in the GlpX-FBP complex (PDB code 3d1r); B, phosphate bound in the
GlpX-phosphate complex (PDB code 3big). The ligand, metal ions (Mg, Ca1, and
Ca2) and selected residues of GlpX (D61A) in contact with the ligand and metal
ions (cyan spheres) are shown as a stick diagram along with
a GlpX ribbon (gray). Difference electron density was calculated by
removing the fructose 1,6-bisphosphate from the final model, followed by
several rounds of maximum likelihood refinement using Refmac5. The resulting
Fo - Fc map was contoured at
4.2σ.