Sequence and structural features of binding site residues in protein-protein complexes

We have developed an energy based approach for identifying the binding site residues in protein-protein complexes. The binding site residues have been analyzed with sequence and structure based parameters such as neighboring residues in the vicinity of binding sites and conformational switching. We observed specific preferences of dipeptides and tripeptides for binding, which is unique to proteinprotein complexes. Our analysis showed that 7% of residues changed their conformations upon proteinprotein complex formation and it is 9.2% and 6.6% in the binding and non-binding sites, respectively. Specifically, the residues Glu, Lys, Leu and Ser changed their conformation from coil to helix/strand and from helix to coil/strand. Leu, Ser, Thr and Val prefer to change their conformation from strand to coil/helix. The results obtained in this study will be helpful for understanding and predicting the binding sites in protein-protein complexes.