Fig. 3
Crystal structure of Gβ1γ1 in complex with Nb5. a The asymmetric unit contains two molecules of both Gβ1γ1 (blue and pink) and Nb5 (greencyan and red) shown in cartoon representation. Key interfaces between Gβ1γ1 and Nb5 are denoted by grey ellipsoids. b Side and top views of the Gβ1γ1-Nb5 complex showing the CDR3 region (red) of Nb5 inserted into the Gβ1-propeller. The 2|F o | - |F c | density (blue) around the CDR3 region was calculated after the final refinement and is contoured at 1.5σ. c Gβγ hot-spot is shared by several Gβγ regulatory proteins, including Gαt (pink), phosducin (PDC, cyan), and G Protein-Coupled Receptor Kinase 2 (GRK2, dark grey). d Overall structure of the heterotrimeric G protein (PDB ID: 5KDO). e Overlay of the interface between the Gβ1γ1-Nb5 complex and heterotrimeric G protein. Schematic representation shows the extent of overlapping (in greencyan background, black residues) between the non-canonical Gβ1γ1-Nb5 complex interface (greencyan residues) and the interface between Gβ1γ1 and Gαt (pink residues)
