Double-stranded DNA
Double stranded DNA is well known nucleotide polymer in which two antiparallel nucleotide strands fold into helical forms. The helical folding gives minor and major grooves to duplex DNA structure. There are three major confirmation of duplex DNA i.e. A-form, B-form and Z-form. The folding of DNA into particular conformation depends on different parameters like hydration level of cell, DNA sequence, direction of supercoiling, chemical modifications of the bases, concentration and the type of metal ions, as well as the presence of polyamines in solution. Duplex DNA has important role in DNA replication, transcription of gene and chromatin remodeling. The double stranded DNA caries genetic information that replicates once in a single cell cycle. Error in this replication causes genomic instability which might leads to cancer. The DNA binding ligands could be potential anticancer agents by inhibition of topoisomerase activity and also act as antiviral compounds by hindering viral DNA replication