2.1 Dataset
The Propairs database of legitimate protein-protein docking complexes enlists crystal structures of bound complexes, defined as biological complexes in the Protein Data Bank (PDB), and their corresponding unbound protein structure(s). A total of 2378 bound complexes that have corresponding unbound structures of the interacting partners were collected. It was ensured that the crystal structures of the bound complex are of better than 3Å resolution. Structures in the bound form were required to have the same oligomeric state as in the unbound form to ensure that the perturbation is not influenced by the docking of any other protein molecule. The dataset was further curated to remove structures with missing residues. Any multiple occupancies were corrected to obtain a conformer with single occupancy, based on highest occupancy value, for all its atoms. 895 chains from a bound complex with interfacial sites were paired with the corresponding chain in the unbound form to make the working dataset for this analysis. The list of all the protein chains along with the analysis of their network information can be found in Supplementary Table 1.