3H7X:
reference: A transition from strong right-handed to canonical left-handed supercoiling in a conserved coiled-coil segment of trimeric autotransporter adhesins., Alvarez BH, Gruber M, Ursinus A, Dunin-Horkawicz S, Lupas AN, Zeth K, J Struct Biol. 2010 Feb 21. PMID: 20178846

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