Figure 4. Interaction model of 2:2:2:2 FGF21/FGFR1c/β‐klotho/HS complex.

This model is obtained by superimposition of FGF21^core structure with the crystal structures of β‐klotho/FGF21‐CT (PDB ID: 5VAQ), FGF23/FGFR1c/α‐klotho (PDB ID: 5W21) and FGF2/FGFR1c/HS dimer (PDB ID: 1FQ9), and is shown as surface representation. FGF21^core is colored orange. β1‐β2 loop of FGF21 (Asp24 to Ala31) directly interacting with FGFR1c is colored magenta. FGF21^CT binding to β‐klotho is colored blue. FGFR1c is colored green. D1, D2 domain, and the receptor binding arm of β‐klotho are colored cyan, lightblue, and pink, respectively.