4CCW:
reference: Crystal structures of two Bacillus carboxylesterases with different enantioselectivities., Rozeboom HJ, Godinho LF, Nardini M, Quax WJ, Dijkstra BW, Biochim Biophys Acta. 2014 Mar;1844(3):567-75. doi: 10.1016/j.bbapap.2014.01.003., Epub 2014 Jan 11. PMID: 24418394

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