TY  - JOUR
A1  - Scheitl, Carolin P. M.
A1  - Okuda, Takumi
A1  - Adelmann, Juliane
A1  - Höbartner, Claudia
T1  - Ribozyme-catalyzed late-stage functionalization and fluorogenic labeling of RNA
JF  - Angewandte Chemie International Edition
N2  - 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.
KW  - Aldehyde Bioconjugation
KW  - Bioorthogonal Tag
KW  - Fluorescence and Crosslinking
KW  - RNA Labelling
KW  - Ribozyme
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-327543
VL  - 62
ER  - 
TY  - JOUR
A1  - Okuda, Takumi
A1  - Lenz, Ann-Kathrin
A1  - Seitz, Florian
A1  - Vogel, Jörg
A1  - Höbartner, Claudia
T1  - A SAM analogue-utilizing ribozyme for site-specific RNA alkylation in living cells
JF  - Nature Chemistry
N2  - Post-transcriptional RNA modification methods are in high demand for site-specific RNA labelling and analysis of RNA functions. In vitro-selected ribozymes are attractive tools for RNA research and have the potential to overcome some of the limitations of chemoenzymatic approaches with repurposed methyltransferases. Here we report an alkyltransferase ribozyme that uses a synthetic, stabilized S-adenosylmethionine (SAM) analogue and catalyses the transfer of a propargyl group to a specific adenosine in the target RNA. Almost quantitative conversion was achieved within 1 h under a wide range of reaction conditions in vitro, including physiological magnesium ion concentrations. A genetically encoded version of the SAM analogue-utilizing ribozyme (SAMURI) was expressed in HEK293T cells, and intracellular propargylation of the target adenosine was confirmed by specific fluorescent labelling. SAMURI is a general tool for the site-specific installation of the smallest tag for azide-alkyne click chemistry, which can be further functionalized with fluorophores, affinity tags or other functional probes.
KW  - Alkyltransferase Ribozyme SAMURI
KW  - Site-specific RNA labelling
KW  - bioorthogonal SAM analogue ProSeDMA
KW  - Chemical modification
KW  - RNA
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-328762
ER  -