Back Gráficu de Ramachandran AST Diagrama de Ramachandran Catalan Ramachandranův diagram Czech Ramachandran-Plot German Gráfico de Ramachandran Spanish Ramachandrani graafik Estonian Ramachandran-kuvaaja Finnish Diagramme de Ramachandran French דיאגרמת ראמצ'נדרן HE Grafico di Ramachandran Italian

Ramachandran plot

Original hard-sphere, reduced-radius, and relaxed-tau φ,ψ regions from Ramachandran, with updated labels and axes
Backbone dihedral angles φ and ψ (and ω). All three angles are at 180° in the conformation shown

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,[1] is a way to visualize energetically allowed regions for backbone dihedral angles ψ against φ of amino acid residues in protein structure. The figure on the left illustrates the definition of the φ and ψ backbone dihedral angles[2] (called φ and φ' by Ramachandran). The ω angle at the peptide bond is normally 180°, since the partial-double-bond character keeps the peptide bond planar.[3] The figure in the top right shows the allowed φ,ψ backbone conformational regions from the Ramachandran et al. 1963 and 1968 hard-sphere calculations: full radius in solid outline, reduced radius in dashed, and relaxed tau (N-Cα-C) angle in dotted lines.[4] Because dihedral angle values are circular and 0° is the same as 360°, the edges of the Ramachandran plot "wrap" right-to-left and bottom-to-top. For instance, the small strip of allowed values along the lower-left edge of the plot are a continuation of the large, extended-chain region at upper left.

A Ramachandran plot generated from human PCNA, a trimeric DNA clamp protein that contains both β-sheet and α-helix (PDB ID 1AXC). The red, brown, and yellow regions represent the favored, allowed, and "generously allowed" regions, respectively, as defined by ProCheck
  1. ^ Ramachandran, G.N.; Ramakrishnan, C.; Sasisekharan, V. (1963). "Stereochemistry of polypeptide chain configurations". Journal of Molecular Biology. 7: 95–9. doi:10.1016/S0022-2836(63)80023-6. PMID 13990617.
  2. ^ Richardson, J.S. (1981). "The Anatomy and Taxonomy of Protein Structure". Anatomy and Taxonomy of Protein Structures. Advances in Protein Chemistry. Vol. 34. pp. 167–339. doi:10.1016/S0065-3233(08)60520-3. ISBN 9780120342341. PMID 7020376.
  3. ^ Pauling, L.; Corey, H.R.; Branson, H. R. (1951). "The Structure of Proteins: Two Hydrogen-Bonded Helical Configurations of the Polypeptide Chain". Proceedings of the National Academy of Sciences of the United States of America. 37 (4): 205–211. Bibcode:1951PNAS...37..205P. doi:10.1073/pnas.37.4.205. PMC 1063337. PMID 14816373.
  4. ^ Ramachandran, G.N.; Sasiskharan, V. (1968). Conformation of polypeptides and proteins. Advances in Protein Chemistry. Vol. 23. pp. 283–437. doi:10.1016/S0065-3233(08)60402-7. ISBN 9780120342235. PMID 4882249.

Developed by StudentB