Accuracy of Comparatively Predicted Base-pairs from 496 16S rRNA Sequences and RNA Contact Distance. A. The RNA contact distance (the number of nucleotides in the RNA sequence that are separates the 5' and 3' base-paired) for all 191,994 base-pairs in comparative structure models is determined and plotted. B. The 191,994 comparatively predicted base-pairs are divided into seven RNA contact distance bins (see Logarithmic Binning of Base-pairs by Contact Distance for 16S rRNA in Methods) represented by columns. The accuracies for all base-pairs in each bin are also plotted as points.