Effects of Protein Binding on DNA G-Quadruplex Structures

The non-canonical G-quadruplex is a unique DNA structure that has received widespread attention because of its potential functions not only in vitro but also in vivo. The G-quadruplex is stabilized by formation of Hoogsteen hydrogen bonds in guanine quartets and involves cation coordination and dehydration. Although a number of proteins have been identified that specifically stabilize and destabilize G-quadruplexes, the effect of the protein binding remains unclear. Here, we review the behaviors of proteins binding to G-quadruplexes. We also discuss analyses of the thermodynamic and binding properties of G-quadruplexes in the complexes formed by histones and thrombins. These studies have helped us to understand the essential features of interaction between G-quadruplexes and proteins