Figure 5.

Topologically equivalent interhelical contacts among Class A, B and F. One representative crystal structure for each class has been included: β₂-adrenoceptor in green, CRF₁ in cyan and SMO receptor in magenta. Extracellular view (A) and intracellular view (B) of the common interhelical contacts are shown as yellow dotted lines. Most of the topologically equivalent network of interactions includes TM1–5 (highlighted by a curved arrow). (C) Schematic representation of the interhelical interaction network where TM helices are presented as circles. If consensus interactions are present between helices a line between the corresponding pair of circles is shown with the number of common contacts indicated. The thickness of the line is linked to the number of contacts between the TM helices.