Photo-controlled binding of MutS to photo-caged DNA duplexes incorporating 4-O-(2-nitrobenzyl) or 4-O-[2-(2-nitrophenyl) propyl]thymidine

Mismatch binding protein MutS binding to bulge structure in DNA duplexes was controlled by UV irradiation. 4-O-(2-Nitrobenzyl) thymidine or 4-O-[2-(2-nitrophenyl) propyl] thymidine was incorporated into DNA duplexes a bulged position. The MutS did not bind to the caged DNA duplexes but bound after removing the 2-nitrobenzyl or 2-(2-nitrophenyl) propyl group by photo-irradiation. By using photo-caged DNA duplex, we revealed that binding of MutS to the uncaged DNA downstream of the T7 RNA promoter weakly inhibited transcription by T7 RNA polymerase. (C) 2016 Published by Elsevier Ltd.