Turning Off Transcription with Bacterial RNA Polymerase through CuAAC Click Reactions of DNA Containing 5-Ethynyluracil.

Copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction in the major groove of DNA containing 5-ethynyluracil (U ) with azides was used for turning off sequence-specific protein-DNA interactions. The concept was first demonstrated on switching off cleavage of short modified DNA by restriction endonuclease BamHI-HF. Finally, DNA template containing U was used for in vitro transcription with E. coli RNA polymerase and the transcription was turned off by CuAAC with 3-azidopropane-1,2-diol or 3-azido-7-hydroxycoumarin.