G-quadruplex structures play important role in regulating gene expression, thus can serve as unique therapeutic targets against a variety of diseases, such as cancer. Information on the structure of G-quadruplexes is crucial for understanding their physiological roles and designing effective drugs. Determining the structures of G-quadruplexes, however, remains a challenge especially for those in double-stranded DNA. In this work, TAN Zheng's team developed a photocleavage footprinting technique to determine the folding topology of the individual G-tract in intramolecular G-quadruplex in both single- and double-stranded nucleic acids. This method is extremely intuitive, straightforward, and requires little expertise. In addition, it can also detect G-quadruplex formation in long single- and double-stranded nucleic acids.
Refer to: Zheng KW, Zhang D, Zhang LX, Hao YH, Zhou X, Tan Z. (2011). "Dissecting the Strand Folding Orientation and Formation of G-Quadruplexes in Single- and Double-Stranded Nucleic Acids by Ligand-Induced Photocleavage Footprinting." J Am Chem Soc. 133(5): 1475-1483.
This work was supported by grants from MSTC and NSFC.