2PJP:
reference: Structural insight into a molecular switch in tandem winged-helix motifs from elongation factor SelB., Soler N, Fourmy D, Yoshizawa S, J Mol Biol. 2007 Jul 20;370(4):728-41. Epub 2007 May 10. PMID: 17537456

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