Fig. 5. Comparison of IL-17F and IL-17A. Two orthogonal views, ‘side’ (A) and ‘front’ (B), of the molecular surface of IL-17F colored according to sequence conservation between IL-17A and F as in Figure 1. The surface of residues that are identical between the two proteins are colored green, homologous residues are colored yellow, while residues that differ significantly are colored white. [The view in (B) is oriented ∼15° rotated from the view in Figure 4B.] Residues forming the cavity are labeled in (A). (C) ‘Cut-away’ view of the surface in (B) showing how the large cavities on either side of IL-17F penetrate deeply into the body of the dimer.