Chemical biology that controls DNA structure and function: Lessons in organic chemistry from nature

Fifty years after the discovery of the double-helical structure of DNA, the complete sequence of the human genome has been determined. All genetic information, which is necessary for life, is written in 30 billion base pairs of DNA. Many diseases, including cancer, and hereditary and viral diseases, can now be understood at the DNA sequence level. Local DNA conformations are also thought to play an important role in biological processes, such as gene expression. Therefore, DNA sequences and local DNA conformations are the targets of novel drugs that would precisely switch certain genes on or off. Modified bases that perform various functions can also be incorporated into defined DNA sequences. DNA can now be synthesized by the phosphoramidite method and amplified by PCR, and by using organisms such as Escherichia coli, DNA becomes a promising unit for nanotechnology applications. In this review, I focus on our efforts in understanding the DNA reactivity, structure, and function of DNA. The prospective uses of the chemical biology of DNA will also be discussed.