Bioorthogonal site-specific labeling of the 5′-cap structure in eukaryotic mRNAs

Abstract

We present a chemo-enzymatic approach for site-specific labeling of 5′-capped RNAs based on bioorthogonal chemistry. A trimethylguanosine synthase was engineered to transfer a terminal azido moiety to the 5′-cap which could be further modified using strain-promoted azide–alkyne cycloaddition (SPAAC).