Figure 2.

Schematic of the Ramachandran plot. (A) original steric map of glycine, in standard (left) and shifted (right) coordinates; (B) revised schematic of glycine, in standard (left) and shifted (right) coordinates; (C) pre-proline. The clustered regions are: grey – sterically allowed; red – α and α_L; yellow – β_S; blue – β_P and β_PR; purple – ζ. See text for explanation of the regions.