. 2014 Mar 25;10(5):1852–1862. doi: 10.1021/ct5000023

Table 1. Key Regions and Residues in HP Urease^a.

region	residue numbers and types^b
pentacoordinate Ni²⁺	LYSα219(CO₂^–), HISα248(δN), HISα274(εN), bridging ^–OH, H₂O
hexacoordinate Ni²⁺	LYSα219(CO₂^–), HISα136(εN), HISα138(εN), ASPα362(CO₂^–), bridging ^–OH, H₂O
flap α-helix 1	α313−α322 GLU-HID-MET-ASP-MET-LEU-MET-VAL-CYS-HIE
flap turn	α323−α329 HIP-LEU-ASP-LYS-SER-ILE-LYS
flap α-helix 2	α330−α336 GLU-ASP-VAL-GLN-PHE-ALA-ASP

Flap residues refer to areas as outlined in the crystal structure. Numbering is according to Ha et al.¹³

HID, HIE, and HIP refer to histidines with protonated δ, ε and both imidazole nitrogens, respectively.

Table 1. Key Regions and Residues in HP Ureasea.