1PKU:
reference: Crystal structure of nucleoside diphosphate kinase required for coleoptile elongation in rice (Oryza sativa L.)., Huang JY, Chang T, Chang CY, Chen CJ, J Struct Biol 2005 Jun;150(3):309-18. Epub 2005 Mar 26. PMID: 15890279

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