Aspects of the disclosure relate to methods, compositions, and systems for editing a DNA sequence encoding an endogenous tRNA into a suppressor tRNA using base editing (e.g., to treat a disease caused by a premature termination codon or PTC). Additional aspects relate to compositions comprising a gRNA configured to bind to a DNA sequence encoding an endogenous tRNA. Other aspects relate to complexes comprising a base editor and a gRNA that are capable of editing an endogenous tRNA into a suppressor tRNA. In some aspects, the disclosure further relates to polynucleotides encoding one or more nucleic acid sequences encoding the gRNAs, vectors comprising the polynucleotides, and/or cells comprising the polynucleotides, complexes, gRNAs, and/or vectors disclosed herein. Additional aspects further relate to kits comprising any one of the compositions, complexes, gRNAs, polynucleotides, vectors, and/or cells disclosed herein.

A method for the production of proteins used in the in vitro transcription (IVT) of messenger RNA (mRNA), wherein the proteins are evaluated for purity and efficacy by the efficiency with which mRNA synthetically derived therefrom, subsequently transfects cells and produces encoded proteins.