Figure 10.

Model of the function of BFA3 during assembly of the CF₁ subcomplex. A, Top view of the α₃β₃ hexamer and side view of the αβ heterodimer. The interacting region AthCF₁βII-2 corresponding to amino acid residues 166 to 275 in Arabidopsis CF₁β is shaded a range of colors (from lime to red) from the N to C terminal. Several residues (Leu-181-Ile-182, Met-217, and Glu-224-Ala-228 in AthCF₁β) critical for the interaction between BFA3 and CF₁β are marked with blue spheres, whereas the residues in mβ6 and mβ7 are marked with gray spheres. Catalytic residues (Gly-175, Lys-178, Thr-179, Glu-204, Arg-205, Glu-208, and Asp-273) in CF₁β are highlighted with pink spheres. B, Model of assembly of the CF₁αβ complex. BFA3 directly interacts with the β-subunit and facilitates the assembly with the CF₁α subunit.