Uncoiling of bacteriophage-φ X174 replicative form deoxyribonucleic acid by ethidium, daunomycin and actinomycin

Abstract

A specific prediction of the intercalation hypothe- sis is that binding of intercalating drug molecules to DNA should be associated with local uncoiling of the double helix (Lerman, 1964; Fuller & Waring, 1964). Evidence that such uncoiling occurs when