| 3BTA: reference: Crystal structure of botulinum neurotoxin type A and implications for toxicity., Lacy DB, Tepp W, Cohen AC, DasGupta BR, Stevens RC, Nat Struct Biol 1998 Oct;5(10):898-902. PMID: 9783750 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).