Figure 1: Figure from "Efficiency of signaling through cytokine receptors depends critically on receptor orientation."

Syed, RS; Reid, SW; Li, C; Cheetham, JC; Aoki, KH; Liu, B;  Zhan, H; Osslund, TD; Chirino, AJ; Zhang, J; Finer-Moore, J; Elliot, S;  Sitney, K; Katz, BA; Matthews, DJ; Wendoloski, JJ; Egrie, J; and Stroud, RM. (1998) 
Nature 395, 511-516 
PDB Accession No.1CN4  (replaced 1BLW)
Review abstract  

Figure 2

Figure 3: Erythropoietin Receptor hot spots are indicated.