Figure 1

Structural representations of the functional domains of Gα _q . The crystal structure of Gα_q (based on the complex with p63RhoGEF and RhoA, PDB ID: 2rgnA) is depicted with the different functional domains highlighted. The top left panel is the Gα_q structure in rainbow colors (blue to red as from N- to C-terminus). Nomenclature of α helices and β strands is according to the first resolved Gα crystal structure [19]. The dotted line divides the structure into two parts, known as the helical and GTPase domains. The other five structures are shown in the same orientation as the top left panel, with the putative interacting domains for Gβγ (green), PLCβ (yellow), p63RhoGEF (p63, light blue), GRK2 (orange) and RGS2 (magenta) highlighted. Mapping of the various interacting domains are based on resolved crystal structures (for Gβγ, PLCβ, p63RhoGEF and GRK2) or structural alignment with other Gα subunit complex structures (for RGS2 in complex with Gα_i3). The bottom panel is a simplified linear representation of Gα_q with the secondary structures belonging to helical (light blue) and GTPase domains (light green) highlighted; α-helices and β-strands are depicted as rectangles and ovals, respectively. The N-terminal helix colored in red remains unresolved in the crystal structure of Gα_q. The corresponding functional domains of the five interacting partners as shown in the molecular models above the schematic are indicated with the same color scheme.