The Ramachandran Number: An Order Parameter for Protein Geometry
Fig 5
Four ways of looking at secondary structure: a) Molecular configurations; b) Ramachandran plot; c) Histogram (-code) of Ramachandran numbers; and (d)
as a function of residue number (for the Σ-sheet we have chosen a single polymer).
Panel (c) provides a compact assay-by-geometry of the residues within molecular structures, while panel (d) shows that one can use to identify the spatial connectivity of domains of secondary structure within a polymer.