Fig. 8. Positive patches in the N-terminus of DGqα (A) Of the 34 residues in the N-terminus of DGqα, 11 are basic, positively charged residues (marked in blue). (B) A three-dimensional model of DGqα mapping the electrostatic potential onto its Connolly molecular surface. The approximate orientation towards the βγ subunits is based on the crystal structures of the heterotrimer (PDB IDs 1GP2 and 1GOT). Superimposed over the molecular surface of DGqα are the electrostatic equipotential contours at +1 (blue mesh) and –1 kT/e (red mesh). As shown by the equipotential contour meshes, the positive patches extend a positive potential (marked with blue arrows), reaching significantly beyond the molecular surface of the protein.