Modeling proteins as residue interaction networks

Proteins are the ultimate carriers of information encoded within genes. The salient feature of proteins is their ability to perform a vast array of function with extraordinary specificity. This specificity of proteins is related directly to their structural conformations, which arises as a result of complex interactions among its constituent amino acid residues. Thus, analyzing proteins through these interactions collectively is an extremely important, interesting and effective way to understand their dynamical and structural properties. This review summarizes recent graph theoretical approaches in the field of amino acid residue interaction networks (RIN), [also known as residue interaction graphs (RIG), protein contact networks (PCN) or residue contact networks (RCN)] and the outcomes thereof. It explains the strengths of network formalism in unraveling various aspects of the complex phenomena, upon which the structure and function of proteins have a direct bearing.