Figure 3. Electrostatic surface of the Stat SH2 domains and interaction sites with the Tip ligand.

(A) Tip114-STAT3, (B) Tip127-STAT3, (C) Tip114-STAT6, and (D) Tip127-STAT6. Positively and negatively charged regions of the STAT surface are colored in blue and red, respectively, and the residues that interact with Tip are labeled in black. The position of the bound residues from Tip (labeled in green) is indicated by a black circle.