A hypothetical structural role for proline residues in the flanking segments of protein-protein interaction sites.

An examination of more than 1600 protein-protein interaction sites indicated that proline is the residue most commonly found near interaction sites. A structural role is distinguished for these proline residues in the flanking segments of protein-protein interaction sites. The unique nature of proline helps protect the integrity and present the sites, thus promoting protein-protein interactions. A novel approach to the design and development of potent peptide drugs and a simple predictive method to identify protein-protein interaction sites directly from the amino acid sequence have been developed based on this finding. The recognition of this structural role for proline has strong implications for protein chemistry and protein engineering.