Figure 6. Structural considerations of FGF12-NaV1.5 and FGF13-NaV1.2.
(A, B) FGF12 Glu87 in (A) and its equivalent residue (FGF13 Glu92 in (B)) are located at the interface with NaV proteins. CaM, calmodulin. (C, D) FGF12 Glu87 in (C) and FGF13 Glu92 in (D) form intermolecular hydrogen bonds with the main-chain oxygen atom of the NaV1.5 Ile1892 and the NaV1.2 Ile1896, respectively. The side chain of Arg52 in the FGF12 complex is not visible; however, its FGF13 equivalent (Arg57) forms a salt bridge and a hydrogen bond with Asp1856 and Glu1894 of NaV1.2.