Reversible photoregulation of DNA B-Z transition by a photochromic nucleoside

Abstract We designed a system using a photochromic nucleoside, which can convert duplex DNA between right-handed and left-handed (B-Z transition) response to light stimuli. Our system DNA can be switched between B-conformation and Z-conformation by irradiating with monochromatic 254 nm and 365 nm light. The transition of DNA against photo was completely reversible.