@phdthesis{Scheitl2023, author = {Scheitl, Carolin P. M.}, title = {In vitro selected ribozymes for RNA methylation and labeling}, doi = {10.25972/OPUS-33004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-330049}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The focus of this work was the development and application of highly efficient RNA catalysts for the site-specific modification of RNA with special focus on methylation. In the course of this thesis, the first methyltransferase ribozyme (MTR1), which uses m6G as the methyl group donor was developed and further characterized. The RNA product was identified as the natural modification m1A. X-Ray crystallography was used to solve the 3D structure of the ribozyme, which directly suggested a plausible reaction meachnism. The MTR1 ribozyme was also successfully repurposed for a nucleobase transformation reaction of a purine nucleoside. This resulted in a formyl-imidazole moiety directly on the intact RNA, which was directly used for further bioconjugation reactions. Finally, additional selections and reselections led to the identification of highly active alkyltransferase ribozymes that can be used for the labeling of various RNA targets}, subject = {Methylierung}, language = {en} } @article{ScheitlOkudaAdelmannetal.2023, author = {Scheitl, Carolin P. M. and Okuda, Takumi and Adelmann, Juliane and H{\"o}bartner, Claudia}, title = {Ribozyme-catalyzed late-stage functionalization and fluorogenic labeling of RNA}, series = {Angewandte Chemie International Edition}, volume = {62}, journal = {Angewandte Chemie International Edition}, doi = {10.1002/anie.202305463}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-327543}, year = {2023}, abstract = {Site-specific introduction of biorthogonal handles into RNAs is in high demand for decorating RNAs with fluorophores, affinity labels or other modifications. Aldehydes represent attractive functional groups for post-synthetic bioconjugation reactions. Here, we report a ribozyme-based method for the synthesis of aldehyde-functionalized RNA by directly converting a purine nucleobase. Using the methyltransferase ribozyme MTR1 as an alkyltransferase, the reaction is initiated by site-specific N1 benzylation of purine, followed by nucleophilic ring opening and spontaneous hydrolysis under mild conditions to yield a 5-amino-4-formylimidazole residue in good yields. The modified nucleotide is accessible to aldehyde-reactive probes, as demonstrated by the conjugation of biotin or fluorescent dyes to short synthetic RNAs and tRNA transcripts. Upon fluorogenic condensation with a 2,3,3-trimethylindole, a novel hemicyanine chromophore was generated directly on the RNA. This work expands the MTR1 ribozyme's area of application from a methyltransferase to a tool for site-specific late-stage functionalization of RNA.}, language = {en} }