2IWB:
reference: Unbound and acylated structures of the MecR1 extracellular antibiotic-sensor domain provide insights into the signal-transduction system that triggers methicillin resistance., Marrero A, Mallorqui-Fernandez G, Guevara T, Garcia-Castellanos R, Gomis-Ruth FX, J Mol Biol. 2006 Aug 18;361(3):506-21. Epub 2006 Jul 7. PMID: 16846613

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