@Present address - Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, United States
Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore-570020, Andhra Pradesh, India
*For correspondence -kjr5n@yahoo.co.in
Actinomycin D (AMD) is used as a model compound to understand supercoiled DNA topology and stability. AMD inhibits the transcriptional process. AMD acts as an intercalating agent blocking the site for RNA polymerase on DNA. In the present investigation, we have studied the effect of AMD on the supercoiling nature (scDNA) of the DNA and also on the stability of single (SSC) and double strand circular (DSC) DNA. The results showed that AMD induced B to A conformational change in scDNA as demonstrated by a red shift in the CD spectra at 272 nm. AMD also altered the stability of scDNA as evidenced by the alterations in melting temperature and also in ethidium bromide binding pattern to DNA. The results clearly indicated that AMD binds to ScDNA and DSC-DNA. The role of altered supercoiling nature of the DNA molecule in gene expression is discussed.
AMD, Supercoiled DNA, DNA topology and Gene expression
