Figure 1

Examples of PPI interfaces in class A and class B complexes. The PDBsum [41] interaction analysis represents interaction residues on either chain with residues shown in different colours based on their properties and the coloured lines joining these residues representing the type of interaction between these residues. Class A complex shows a surface polariy of 60.28% and interface polarity of 37.84% (S>I) implying relatively less polar interactions at the interface (or relative abundance of non-polar interactions at the interface). Class B complex shows surface polariy of 50.69% and an interface polarity of 73.21% (S<I) implying relative abundance of polar interactions at the interface (or relatively less non-polar interactions at the interface).