The duplex-helix structure of DNA with Watson-Crick base pairs of G.C and A:T are important carrier of storing, expressing and transferring genetic information. This special base matching form is useful to stabilize nucleic acid structure. The distribution of functional groups in major and minor groove are propitious to the interaction between DNA and protein enzyme, metal ion and metal complex with biological functional. DNA replication must be very accurate in order to pass genetic information to next gen...