1XHS:
reference: Solution NMR structure of Escherichia coli ytfP expands the structural coverage of the UPF0131 protein domain family., Aramini JM, Huang YJ, Swapna GV, Cort JR, Rajan PK, Xiao R, Shastry R, Acton TB, Liu J, Rost B, Kennedy MA, Montelione GT, Proteins. 2007 Aug 15;68(3):789-95. PMID: 17523190

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