4LPS:
reference: Relationship between Ni(II) and Zn(II) Coordination and Nucleotide Binding by the Helicobacter pylori [NiFe]-Hydrogenase and Urease Maturation Factor HypB., Sydor AM, Lebrette H, Ariyakumaran R, Cavazza C, Zamble DB, J Biol Chem. 2014 Feb 14;289(7):3828-41. doi: 10.1074/jbc.M113.502781. Epub 2013 , Dec 12. PMID: 24338018

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).