1BPL:
reference: Crystal structure of calcium-depleted Bacillus licheniformis alpha-amylase at 2.2 A resolution., Machius M, Wiegand G, Huber R, J Mol Biol 1995 Mar 3;246(4):545-59. PMID: 7877175

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