Fig. 5: Active site of Y. enterocolitica urease.

a Overview of urease assembly with the active site location indicated. Inset shows in top panel side view of urease crystal structures from S. pasteurii mobile flap shown in open conformation in salmon (PDB: 2UBP) and in closed position as light purple (PDB: 3UBP). In gray the cryo-EM structure of Y. enterocolitica is overlaid and the green spheres represent the Ni²⁺ ions of the active site. Bottom panel shows top view of the three structures. Arrows indicate movement of helix and catalytic His325 is shown as stick. b Model of active site residues and Ni²⁺ ions with the cryo-EM map of Y. enterocolitica at 1.98 Å nominal resolution. Yellow line indicates distance between Ni²⁺ ions in Å; c shows the water molecules in the active site. d Crystal structure of K. aerogenes urease at 1.9 Å resolution (PDB: 1EJW). Yellow line indicates distance between Ni²⁺ ions in Å. e Crystal structure of S. pasteurii at 1.28 Å with inhibitor NBPT (PDB: 5OL4).