Novel trinucleotide mRNA capping reagents: improved synthetic route and efficient cotranscriptional incorporation in mRNA

Structure of “d(TCCT)” DNA template, T7 promoter, and alternative forms of mRNA that could potentially form on this template with or without TCP (^7mGpppA_mpG or ^7mGppp^6mA_mpG). Entries 4 and 6 show the ^7mGpppA_mpG and ^7mGppp^6mA_mpG structures in reverse orientation; however, formation of respective reverse TCP-mRNAs was not detected (see below). Positions of transcription start site and DNAzyme cleavage site are shown with arrows.