4QWP:
reference: Structural and biochemical insights into the degradation mechanism of chitosan by chitosanase OU01., Lyu Q, Shi Y, Wang S, Yang Y, Han B, Liu W, Jones DN, Liu W, Biochim Biophys Acta. 2015 Jul 2;1850(9):1953-1961. doi:, 10.1016/j.bbagen.2015.06.011. PMID: 26145578

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