2.2. Amino acid residues interaction analysis
The web server of Protein Contacts Atlas( http://www.mrc-lmb.cam.ac.uk/pca/) was applied for
analysis of non-covalent contacts, such as hydrogen bonds, hydrophobic
interactions, cation-pi interactions, salt bridges, and etc. The default
threshold of the atoms’ distance for interaction calculations is set as
0.5 Å. Multiple non-covalent contacts at different scales of structure,
namely, amino acid residues, secondary structure, subunits, and entire
complexes were analyzed[19]. Protein side-chain networks (PScN) is
then constructed by setting amino acid residues as nodes. The edges are
constructed between the nodes based on non-covalent interactions,
side-chain interaction between them.