FIGURE 2.

Designed peptides with S2 improper rotational symmetry. Unless noted otherwise, columns and colors are as in Figure 1. The symmetry is illustrated with left and right hands, shown in green and orange respectively, in icons in column a. Centers of inversion are shown as black spheres in columns a and e. In column d, pink and light blue ovals indicate the first and second symmetry lobes, respectively, which are related to one another by mirroring (a 180° rotation about the origin in Ramachandran space). Bright red and bright blue points represent the design, and dark red and dark blue points represent the crystal structure. (I–VI) Peptides S2‐1–S2‐6. In each of peptides S2‐4 and S2‐5, two designed backbone‐backbone hydrogen bonds were observed to be replaced with a bridging water molecule in the crystal structure (dashed purple lines in column e)