Figure 4: Positions of the 28 alanine replacements mapped to the APC1 model.

(a) View from the membrane and (b) view from the cytoplasmic side of the APC1 model. The mutations are shown as spheres and they are colored according to clusters identified in Fig. 3b. The regulatory domain (blue) is based on the APC1 regulatory domain crystal structure (PDB: 4ZCV)12. The carrier domain (grey) is a comparative homology model based on the crystal structure of bovine AAC (PDB: 1OKC)16,49. The linker-loop structure is based on evolutionary coupling data (Supplementary Fig. 8 and Supplementary Table 2).