What is Ramachandran plot and its significance?
The Ramachandran plot provides a way to view the distribution of torsion angles in a protein structure and shows that the torsion angles corresponding to the two major secondary structure elements (α-helices and β-sheets) are clearly clustered within separate regions.
What are the principle underlying the formation of Ramachandran plot?
The Ramachandran Principle says that alpha helices, beta strands, and turns are the most likely conformations for a polypeptide chain to adopt, because most other conformations are impossible due to steric collisions between atoms. The other atoms are fragments of adjacent amino acids2.
What is Psi and phi?
As with any peptide the conformation of the backbone is determined by the values of two torsional angles. In sequence order, phi (φ) is the C(i-1),N(i),Ca(i),C(i) torsion angle and psi (ψ) is the N(i),Ca(i),C(i),N(i+1) torsion angle.
What is Ramachandran plot biology discussion?
Plots of phi versus psi dihedral angles for amino acid residues are called Ramachandran plots. One can tell if the backbone is following a helical or an extended beta strand structure based on the values of the phi-psi angles over a length of backbone (usually 3-4 residues is sufficient).
What is a Psi angle?
The angle between two bonds The backbone of a protein has three different torsion angles. The phi-angle (φ) – around the N-Cα bond. The psi-angle (ψ) – around the Cα-C bond. The omega-angle (ω) – around the peptide bond between C and N.
Who is the creator of the Ramachandran plot?
In biochemistry, a Ramachandran plot (also known as a Rama plot, a Ramachandran diagram or a [φ,ψ] plot), originally developed in 1963 by G. N. Ramachandran, C. Ramakrishnan, and V. Sasisekharan, is a way to visualize energetically allowed regions for backbone dihedral angles ψ against φ of amino acid residues in protein structure.
Which is the vertical axis of the Ramachandran plot?
The horizontal axis on the plot shows φ values, while the vertical shows ψ values. Both horizontal and vertical axes start from -180 and extend to +180. The images also show that φ and ψ angles of α-helices and β-sheets are separated and occupy different regions of the plot (marked as α and β).
What does the Ramachandran plot show about an amino acid?
The Ramachandran plot shows the statistical distribution of the combinations of the backbone dihedral angles ϕ and ψ. In theory, the allowed regions of the Ramachandran plot show which values of the Phi/Psi angles are possible for an amino acid, X, in a ala-X-ala tripeptide (Ramachandran et al., 1963 ).
How to plot backbone dihedral angles on Ramachandran plot?
Plots You can upload a PDB-formatted file to the server and the backbone dihedral angles will be plotted on our accurate Ramachandran Plot Instructions: Select a protein structure file in PDB format from your hard disk. Select Amino Acid type to show.
