Department of Chemistry University of Delhi, Delhi 110 007, India.
Nucleic acids (DNA/RNA) are the functional forms of polynucleotides. For years after description of the right-handed DNA double helix by Watson and Crick, DNA was viewed as uniform molecule. But considering the sequence – dependent, pH & cation – dependent, structural variations in solution, the concept of a monotonous double helix is no more in celebration at present times. Sequence dependent structural heterogeneity in the conformation, play a critical role in monitoring interactions of nucleic acids with both large and small substrates. Possibility of Intramolecular triplexes and quadruplexes acting as gene regulatory elements, have further enriched our understanding of nucleic function. Perhaps equally importantly, they provide new opportunities for intervention leading to further mechanistic understanding and therapeutic gain.
I will discuss here in brief, how the sequence, cation-type and solution pH dictates the conformational flexibility of DNA and generation of a galaxy of unimolecular to multistranded helices. Polymorphism of DNA is important for interactions with proteins or drugs. Read more…