Figure 12.

The definition of the coordinate of CESS. The definition of coordinate of CESS v^para, and v^perp for (a) an α helix and (b) a β strand are depicted. In the upper parts, an α helix and a β strand are depicted by a ribbon diagram, as well as by a ball-and-stick C_α model. Black balls represents C_α atoms of i-th SSSSE that starts from k-th residue. Gray balls represents ${\mathit{r}}_i^{\text{CESS}}$. In the lower parts, ${\mathit{v}}_i^{\text{para}}$ and ${\mathit{v}}_i^{\text{perp}}$ of the CESS are indicated by dashed arrows colored in blue and red, respectively. (c) An example of schematic representation of a β - α - β motif by a set of CESSs.