1C4K:
reference: Three-dimensional structure of the Gly121Tyr dimeric form of ornithine decarboxylase from Lactobacillus 30a., Vitali J, Carroll D, Chaudhry RG, Hackert ML, Acta Crystallogr D Biol Crystallogr 1999 Dec;55 ( Pt 12):1978-85. PMID: 10666573

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