1AIV:
reference: Crystal structure of hen apo-ovotransferrin. Both lobes adopt an open conformation upon loss of iron., Kurokawa H, Dewan JC, Mikami B, Sacchettini JC, Hirose M, J Biol Chem 1999 Oct 1;274(40):28445-52. PMID: 10497206

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