Figure 4.
(a) Structure of the pSTAT3 dimer: SH2 domain at the top, bound to a phosphopeptide ligand (wireframe) of the complementary molecule. The central DNA-binding domain bound to dsDNA (orange). The CCD is shown in the inset, with the site of rhodium-catalyzed labeling (Phe174) in purple and the Asp170 residue (green), identified previously as a residue controlling STAT3 function. See text for discussion. (b) STAT3 coiled-coil region, indicating a lack of Lewis-basic (H, M, C) residues (orange).