# Pairwise contact cutoffs [A] for ligand functional groups and amino acid residues ligand/residue | ALA ARG CYS PRO LEU ILE GLU HIS TRP THR MET ASP GLY PHE LYS GLN SER ASN TYR VAL --------------------------------------------------------------------------------------------------------------------- aromatic rings | 5.6 7.1 5.6 6.5 6.7 6.8 7.1 6.6 7.4 6.5 6.6 6.5 5.5 6.9 6.9 6.9 5.8 6.3 7.2 6.5 ether | 5.6 6.7 5.8 5.8 6.6 6.4 6.0 6.2 7.0 6.2 6.5 5.7 5.0 6.8 6.3 6.0 5.3 5.7 6.8 6.4 thioether | 6.1 7.7 6.7 6.8 7.1 7.2 7.4 7.1 7.8 6.7 7.0 6.8 5.9 7.5 7.5 7.2 6.4 6.9 7.5 6.8 carbonyl | 5.0 6.5 5.6 5.8 6.4 6.0 5.6 5.8 6.7 5.7 6.0 5.4 4.7 6.0 6.0 5.6 4.7 5.9 6.6 6.0 thiocarbonyl | 6.3 7.9 6.2 6.0 6.6 6.0 6.2 6.1 6.9 5.8 8.5 6.1 4.3 6.9 6.7 6.3 6.0 6.6 7.7 6.9 halogene | 4.8 7.0 4.7 5.1 5.9 6.0 5.8 5.6 6.7 6.3 6.3 5.7 4.6 6.0 5.9 5.9 5.2 5.4 6.0 5.8 guanidine | 5.6 7.4 5.6 7.2 6.7 7.3 7.1 6.5 7.5 6.9 6.6 7.1 5.7 8.0 7.8 6.9 6.3 7.3 7.4 7.0 amide | 4.9 6.5 5.3 5.9 6.5 6.3 6.3 6.5 7.1 5.8 6.1 5.8 4.9 6.7 6.8 6.7 5.7 6.1 6.7 5.8 carboxyl | 5.5 7.2 5.6 6.1 6.5 6.4 6.4 6.8 7.1 6.2 7.0 6.2 5.3 6.6 7.3 6.8 6.0 6.4 7.1 6.3 amine | 4.5 6.1 4.5 5.0 5.2 5.3 5.3 5.4 6.5 5.1 5.6 4.9 4.0 5.7 6.0 5.5 4.4 4.8 6.2 5.1 phosphate | 5.3 7.8 5.7 7.2 6.8 7.2 7.2 7.1 8.3 6.1 6.8 7.0 5.9 7.6 7.5 7.1 6.0 6.6 7.5 7.0 sulphate | 5.6 6.8 5.4 6.1 6.4 6.8 6.6 6.1 7.9 7.0 7.1 7.1 5.9 7.4 7.2 7.6 5.8 6.5 7.2 6.4 nitro group | 5.3 6.4 4.9 5.5 5.8 6.7 5.5 5.0 6.9 6.2 6.3 6.1 4.7 6.3 5.6 6.8 5.4 5.4 6.9 6.2 metals | 5.4 7.0 3.7 5.7 4.9 5.2 5.8 4.7 6.7 3.7 4.4 5.6 4.8 5.9 6.6 5.4 3.7 4.9 4.8 6.0 hydroxyl | 4.2 6.4 4.6 5.8 5.9 5.8 5.6 5.7 6.4 5.4 5.6 4.8 4.1 6.2 6.1 5.9 5.1 5.2 6.2 5.7 thiol | 5.5 6.8 5.1 6.0 6.3 6.7 6.0 6.0 6.4 6.0 7.6 6.4 4.5 6.2 6.8 6.2 4.9 6.4 7.3 6.2 aliphatic chain | 5.8 7.6 5.9 7.1 7.2 7.4 6.8 6.6 7.9 6.9 7.4 6.7 5.8 7.5 7.5 7.0 6.2 6.8 7.5 7.1