Dihedral angles converted to Ramachandran numbers can be recovered only approximately, but the error incurred during this back-mapping can be made much smaller than the standard error (typically 1Å) associated with structures in the protein databank.
<p>Here we show the root-mean-squared-deviation (RMSD) in dihedral angles (a) and in protein <i>α</i>-carbon spatial coordinates (b) generated upon taking 8560 protein structures obtained from SCOP [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160023#pone.0160023.ref036" target="_blank">36</a>], converting their dihedral angles to Ramachandran numbers, and recovering approximately those dihedral angles using Eqs (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160023#pone.0160023.e022" target="_blank">7</a>) and (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160023#pone.0160023.e023" target="_blank">8</a>). The parameter <i>σ</i> indicates the grid resolution used to calculate <i>R</i>; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160023#pone.0160023.e009" target="_blank">Eq (1)</a>.</p
