2PRD:
reference: Crystal structure of inorganic pyrophosphatase from Thermus thermophilus., Teplyakov A, Obmolova G, Wilson KS, Ishii K, Kaji H, Samejima T, Kuranova I, Protein Sci 1994 Jul;3(7):1098-107. PMID: 7920256

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