4X0I:
reference: Structural basis for ligand and innate immunity factor uptake by the trypanosome haptoglobin-haemoglobin receptor., Lane-Serff H, MacGregor P, Lowe E, Carrington M, Higgins M, Elife. 2014 Dec 12;3. doi: 10.7554/eLife.05553. PMID: 25497229

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