Mixed cartoon-surface representations of receptor/ligand complexes of (A) Type I IL4 ternary complex (PDB ID:3BPL) comprising IL4Rα:IL4:γ
and (B) Type II IL4 ternary complex (PDB ID:3BPN) comprising IL4Rα:IL4:IL13Rα1. Receptor residues making van der Waals contact (<4 Å) with residues in IL4 site 1, site 2, and site 3 epitopes are highlighted in pink, blue and violet, respectively. Labeled is positively selected residue T28 in IL4 site 3 and IL13Rα1 site 3-binding residues (K77, K76 and I78). Coloring scheme for IL4 was retained from Figure 3.