Figure 2.

Histograms of IDIs between sets of identical (upper left), isosteric (upper right), near isosteric (lower left) and non-isosteric (lower right) base pair instances from the 3D structures in the reduced-redundancy dataset having better than 3.0 Å resolution. Upper left: IDIs calculated between identical base pairs (i.e. GC cWW with GC cWW, UA tWH with UA tWH, etc.). Upper right: IDIs between 200 GC cWW and 200 UA cWW pairs. Lower left: IDIs between 200 GC cWW and 200 GU cWW pairs. Lower right: IDIs between 200 GU cWW and 200 UG cWW pairs.