Viewing G-factors in 3DThe G-factors provide a measure of how "normal", or alternatively how "unusual", a given stereochemical property is. There are two types computed by PROCHECK: torsion angle G-factors and covalent geometry G-factors.
The former can be viewed mapped onto the 3D structure of the protein in question if you have your browser configured to view RasMol scripts. (For more information on this, click here).
The torsion angle G-factors are as follows:
Where a particular torsion angle's G-factor is unusual (ie <-2.0) the central bond defined by the torsion angle is highlighted in the structure as follows:
Thus a quick look at the structure can often show the regions, or merely the isolated residues, that appear to have unusual geometry.