Structure of Symfoil-II in space group C2. (a) Overall structure of Symfoil-II represented by a ribbon model. The first repeat (residues 12–53 in Fig. 1) is colored in green, the second repeat (54–95) is colored in cyan and the third repeat (96–137) is colored in orange. (b) Structure of N- and C-terminal residues in Symfoil-II. The 2Fo − Fc electron density map is contoured at the 1.0σ level.