2NNE:
reference: Identification of the retinol-binding protein (RBP) interaction site and functional state of RBPs for the membrane receptor., Redondo C, Vouropoulou M, Evans J, Findlay JB, FASEB J. 2008 Apr;22(4):1043-54. Epub 2007 Nov 8. PMID: 17991731

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