| 4I8C: reference: The binding mode of Ni-((L)-His)(2) in NikA revealed by X-ray crystallography., Lebrette H, Iannello M, Fontecilla-Camps JC, Cavazza C, J Inorg Biochem. 2012 Dec 23;121C:16-18. doi: 10.1016/j.jinorgbio.2012.12.010. PMID: 23314594 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).