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## Section: New Results

### Implementation of an Interactive Ramachandran Plot Element for SAMSON

Participants : Guillaume Pages, Sergei Grudinin.

Each residue of a protein have two degrees of conformational freedom, described by the two dihedral angles of the backbone $\phi$ and $\psi$. Those two angles are crucial to visualize since they determine most of the protein backbone's overall conformation. A very useful way to represent them has been proposed by Ramachandran, Sasisekharan, and Ramakrishnan in 1963 [63].

We have developed a SAMSON element for displaying and editing the Ramachandran Plot of a protein. The favoured regions of the plot have been determined by analysing a database of high quality solved protein structure, provided on Richardson Lab's website (http://kinemage.biochem.duke.edu/databases/top8000.php).

Figure 22. The Ramachandran plot element