Ramachandran plot
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 a…
Full Answer
What does MolProbity score mean?
"[The MolProbity score] is a log-weighted combination of the clashscore, percentage Ramachandran not favored and percentage bad side-chain rotamers, giving one number that reflects the crystallographic resolution at which those values would be expected.
What is the purpose for MolProbity?
Purpose. MolProbity provides the user with an expert-system consultation about the accuracy of a macromolecular structure model, diagnosing local problems and enabling their correction.
What does Clashscore mean?
clashscore (plural clashscores) (chemistry, of a molecular model) A numerical indication of how many pairs of atoms are unusually close together.
What are favored Rotamers?
In the new system developed here, a score of <0.3% qualifies as a rotamer outlier – its score is worse than 99.7% of the good data. Scores ≥ 0.3% and < 2.0% are considered allowed while those ≥ 2.0% are considered favored, as is traditional for Ramachandran criteria [18, 28].
What does a Ramachandran plot show?
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 do you reference MolProbity?
Cite MolProbity: Chen et al. (2010) MolProbity: all-atom structure validation for macromolecular crystallography. Acta Crystallographica D66:12-21. Davis et al.
What is a Ramachandran outlier?
Ramachandran outliers are those amino acids with non-favorable dihedral angles, and the Ramachandran plot is a powerful tool for making those evident. Most of the time, Ramachandran outliers are a consequence of mistakes during the data processing.
What is Rmsd in protein structures?
Root mean square deviation (RMSD) is used for measuring the difference between the backbones of a protein from its initial structural conformation to its final position. The stability of the protein relative to its conformation can be determined by the deviations produced during the course of its simulation.
What is Verify3D?
Verify3D derives a“3D-1D” profile based on the local environment of each residue, described by the statistical preferences for the following criteria: the area of the residue that is buried, the fraction of side-chain area that is covered by polar atoms (oxygen and nitrogen), and the local secondary structure.
What is a Rotamer protein?
In proteins, the sidechain of an amino acid can take different positions. These positions are called rotamers. Foldit puzzles may also contain non-protein molecules called ligands. In some cases, small molecule ligands may have multiple rotamers as well.
What is CaBLAM outlier?
As a general rule, CaBLAM outliers usually indicate a problem with the orientations for one or more peptide planes. Look for a way to reorient the peptide either to remove clashes or establish hydrogen bonds.
How do you cite Pdbsum?
PDBsum is a database that provides an overview of the contents of each 3D macromolecular structure deposited in the Protein Data Bank....PDBsum.ContentAuthorsRoman Laskowski & al. (1997)Primary citationPMID 9433130AccessWebsitewww.ebi.ac.uk/pdbsum/8 more rows
When was the Ramachandran plot first calculated?
The first Ramachandran plot was calculated just after the first protein structure at atomic resolution was determined ( myoglobin, in 1960 ), although the conclusions were based on small-molecule crystallography of short peptides.
What is the angle of a Ramachandran plot?
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, is a way to visualize energetically allowed regions for backbone dihedral angles ψ against φ ...
Walkthroughs & tutorials
Evaluate X-ray structure: Typical steps for a published X-ray crystal structure or one still undergoing refinement.
What's new in 4.1
Validation analysis now powered by CCTBX. Also adds geometry regularization for N/Q/H flip corrections. Read more about this change here.
Common questions
Cite MolProbity : Chen et al. (2010) MolProbity: all-atom structure validation for macromolecular crystallography. Acta Crystallographica D66:12-21.
Overview
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. The figure on the left illustrates the definitio…
Uses
A Ramachandran plot can be used in two somewhat different ways. One is to show in theory which values, or conformations, of the ψ and φ angles are possible for an amino-acid residue in a protein (as at top right). A second is to show the empirical distribution of datapoints observed in a single structure (as at right, here) in usage for structure validation, or else in a database of many structures (as in the lower 3 plots at left). Either case is usually shown against outlines for the th…
Amino-acid preferences
One might expect that larger side chains would result in more restrictions and consequently a smaller allowable region in the Ramachandran plot, but the effect of side chains is small. In practice, the major effect seen is that of the presence or absence of the methylene group at Cβ. Glycine has only a hydrogen atom for its side chain, with a much smaller van der Waals radius than the CH3, CH2, or CH group that starts the side chain of all other amino acids. Hence it is least re…
More recent updates
The first Ramachandran plot was calculated just after the first protein structure at atomic resolution was determined (myoglobin, in 1960 ), although the conclusions were based on small-molecule crystallography of short peptides. Now, many decades later, there are tens of thousands of high-resolution protein structures determined by X-ray crystallography and deposited in the Protein Data Bank (PDB). Many studies have taken advantage of this data to produce more detai…
Related conventions
One can also plot the dihedral angles in polysaccharides (e.g. with CARP).
Gallery
• Ramachandran plot for the general case; data from Lovell 2003
• Ramachandran plot for Glycine
• Ramachandran plot for Proline
• Ramachandran plot for pre-Proline
Software
• Web-based Structural Analysis tool for any uploaded PDB file, producing Ramachandran plots, computing dihedral angles and extracting sequence from PDB
• Web-based tool showing Ramachandran plot of any PDB entry
• MolProbity web service that produces Ramachandran plots and other validation of any PDB-format file
Further reading
• 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., available on-line at Anatax
• Branden, C.-I.; Tooze, J. (1991), Introduction to Protein Structure, Garland Publishing, NY, ISBN 0-8153-0344-0