5XPE:
reference: Neutron structure of the T26H mutant of T4 phage lysozyme provides insight into the catalytic activity of the mutant enzyme and how it differs from that of wild type., Hiromoto T, Meilleur F, Shimizu R, Shibazaki C, Adachi M, Tamada T, Kuroki R, Protein Sci. 2017 Oct;26(10):1953-1963. doi: 10.1002/pro.3230. Epub 2017 Jul 25. PMID: 28707339

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