Tutorial:Ramachandran Plot Inspection

Dihedral angles (ϕ and ψ) in proteins and the Ramachandran plot

Structure	Ramachandran plot	ϕ = phi ψ = psi While dragging in the plot, restrict to: none constant phi constant psi Or enter values: ϕ = ψ = Structure rotation changing one angle: Highlights: (do not work during rotation) collisions or clashes (steric hindrance) ϕψ
Retrieve structure by PDB ID: PDB ID: Chain: Residue nr.: PDB @ USA PDB @ Europe Proteopedia	(drag the purple point around) ϕ ψ Legend for Ramachandran plot: ━━━ boundary of rather stable conformations (favoured) ━ ━ boundary of moderately stable conformations (allowed) α alpha helix (right-handed, the usual one) Lα left-handed alpha helix (uncommon) 3₁₀ 3(10) helix β beta strand, beta sheet poly P polyproline helix (also collagen)

You may visit the Ramachandran Plot page for a thorough description of the features and meaning of this plot, as well as examples in whole proteins.

Note: for lack of a one-letter standard abbreviation, Π is used here for hydroxyproline in the sequence.

Image of Ramachandran plot areas modified from “Ramachandran_plot_original_outlines” by Dcrjsr [CC-BY license]