4IZC:
reference: Crystal Structure of DmdD, a Crotonase Superfamily Enzyme That Catalyzes the Hydration and Hydrolysis of Methylthioacryloyl-CoA., Tan D, Crabb WM, Whitman WB, Tong L, PLoS One. 2013 May 21;8(5):e63870. doi: 10.1371/journal.pone.0063870. Print 2013. PMID: 23704947

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