5EHB:
reference: A De Novo Designed Coiled-Coil Peptide with a Reversible pH-Induced Oligomerization Switch., Lizatovic R, Aurelius O, Stenstrom O, Drakenberg T, Akke M, Logan DT, Andre I, Structure. 2016 Jun 7;24(6):946-55. doi: 10.1016/j.str.2016.03.027. Epub 2016 May, 5. PMID: 27161978

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