6NC9:
reference: Visualizing conformation transitions of the Lipid II flippase MurJ., Kuk ACY, Hao A, Guan Z, Lee SY, Nat Commun. 2019 Apr 15;10(1):1736. doi: 10.1038/s41467-019-09658-0. PMID: 30988294

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