Fidelity of nucleotide incorporation by RNA polymerases

Polymerase fidelity describes the propensity of an enzyme for insertion of incorrect nucleotides during mRNA synthesis. Faithful transcription of a DNA template into mRNA is necessary to generate the correct therapeutic protein in vivo, and T7 RNA polymerase has sufficiently high fidelity to synthesize efficacious mRNA drugs. As mRNA technologies develop, e.g., in the use of longer transcripts or molecules containing novel modified nucleotides, there is a need to understand the determinants of polymerase fidelity and produce high-fidelity enzymes. A key goal in our group is to determine the fidelity of incorporation of modified nucleotides by novel RNA polymerases and develop superior enzymes for the next generation of mRNA therapeutics.