Figure 3. Contrasting the fold specificity of protein contact maps (PCMs) and protein core atomic interaction networks (PCAINs).

Averaged intra-family (diagonal) and inter-family (non-diagonal) correlation coefficients of (A.) PCMs and (B.) PCAINs were computed at 5 angstroms threshold distance ρ and normalized solvent accessibility/atom of ω = 10 on a family-by-family basis for several prominent folds of the protein universe. The complete 1018 folds by 1018 folds correlations of PCMs and PCAINs for the entire fold universe is shown in supplementary figure S5. From these figures it is clear that PCAIN is highly fold-specific but PCM shows no discernible fold specificity.