1N7W:
reference: The position of arginine 124 controls the rate of iron release from the N-lobe of human serum transferrin. A structural study., Adams TE, Mason AB, He QY, Halbrooks PJ, Briggs SK, Smith VC, MacGillivray RT, Everse SJ, J Biol Chem 2003 Feb 21;278(8):6027-33. Epub 2002 Nov 27. PMID: 12458193

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