Fig. 2: Dimerization interface of the NHE1-CHP1 complex.

a Helices from the dimerization domains in the NHE1-CHP1^K/cariporide complex shown in cartoon. Four regions involved in dimerization are boxed. b Interactions between EL1 and TM7′ or TM8′ in the extracellular side. Hydrophobic residues are shown as sticks. c Hydrophobic cavity between the two dimerization domains facing the extracellular side. Aromatic amino acid residues and putative lipids (salmon) within the cavity are shown as sticks. d Hydrophobic interactions between TMs 1, 8, and 10 from one protomer and TMs 8′ and 10′ from another protomer. Sidechains of residues in dimer contact are showed in sticks. The 2-fold symmetry axis is depicted as a black oval. e Dimerization of the HC3 helices around the 2-fold axis. f Structural comparison of the dimerization domain between NHE1-CHP1^K/cariporide complex (in blue) and the NHE1-CHP1^Na/7.5 complex (in red). The core domain is depicted as a gray surface model. The displacements of helix and helix bending are indicated. The Cα atom of G305 is shown as a sphere. The 2-fold symmetric axis is depicted as a dash line.