Table 1.

Relative binding free energies (in kcal/mol) between H3 tails and HP1 chromodomain. These values were calculated with the thermodynamic integration method by “alchemically” transforming the residue at position 9 of H3 tail from one to another, specifically, from KMe3 to tBuNle, tBuNle to MeNle, and MeNle to LYS. The transformations were performed for HP1 chromodomain – H3 tail complexes and H3 tails in solution and the relative binding free energies were obtained by taking the difference of the results from simulations in complex and in solution

System	run 1	run 2	average
KMe3 -> tBuNle	3.2	3.0	3.1±0.1
tBuNle -> MeNle	2.1	1.7	1.9±0.2
LYS -> MeNle	2.3	1.9	2.1±0.2