Figure 4. Distributions of densities of correlated mutations at positions involved in long-range interactions for different classes of lattice folds with increasing values of average contact-frequency.

The 1081 different folds of 25 residue-long sequences on a 5×5 lattice were ordered according to their average contact frequency, (), and then divided into three equal-sized groups comprising the folds with the lowest (A), in between (B) and highest (C) values of , respectively. It can be seen that the density of correlated mutations tends to increase as the average contact-frequency of the fold increases.