Figure 7.

Dimer arrangement of the active state AT₁R bound with an Ang II analog and nanobodies. (A) The complex between the Ang II analog, AT₁R, and active state stabilizing nanobodies has been crystallized as a homodimer [PDB ID: 6do1 (62)]. The interface between the protomers is constituted by hydrophobic and aromatic amino acid side chain contacts at EL1 (M90, F96), TM1 (F55, intracellularly), TM2 (Y99), and helix 3 (L100). (B) In a putative scenario of a dimeric receptor arrangement with antibody binding at one protomer, the Fab fragment should also simultaneously contact the second receptor protomer. For this model, the AT₂R structure (6jod), with and without a Fab, were arranged together as suggested by the AT₁R homodimer.