4HZF:
reference: Modulation of global low-frequency motions underlies allosteric regulation: demonstration in CRP/FNR family transcription factors., Rodgers TL, Townsend PD, Burnell D, Jones ML, Richards SA, McLeish TC, Pohl E, Wilson MR, Cann MJ, PLoS Biol. 2013 Sep;11(9):e1001651. doi: 10.1371/journal.pbio.1001651. Epub 2013 , Sep 10. PMID: 24058293

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