1Y8S:
reference: A structural model for the osmosensor, transporter, and osmoregulator ProP of Escherichia coli., Wood JM, Culham DE, Hillar A, Vernikovska YI, Liu F, Boggs JM, Keates RA, Biochemistry. 2005 Apr 19;44(15):5634-46. PMID: 15823022

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