1ERN:
reference: Crystallographic evidence for preformed dimers of erythropoietin receptor before ligand activation., Livnah O, Stura EA, Middleton SA, Johnson DL, Jolliffe LK, Wilson IA, Science 1999 Feb 12;283(5404):987-90. PMID: 9974392

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