N⁶‐Isopentenyladenosine in RNA Determines the Cleavage Site of Endonuclease Deoxyribozymes

Abstract

RNA-cleaving deoxyribozymes can serve as selective sensors and catalysts to examine the modification state of RNA. However,s ite-specific endonuclease deoxyribozymes that selectively cleave post-transcriptionally modified RNAare extremely rare and their specificity over unmodified RNAi s low.W ereport that the native tRNAmodification N 6-isopentenyladenosine (i 6 A) strongly enhances the specificity and has the power to reconfigure the active site of an RNA-cleaving deoxyribozyme.Using in vitro selection, we identified aDNA enzyme that cleaves i 6 A-modified RNAatleast 2500-fold faster than unmodified RNA. Another deoxyribozyme shows unique and unprecedented behaviour by shifting its cleavage site in the presence of the i 6 AR NA modification. Together with deoxyribozymes that are strongly inhibited by i 6 A, these results highlight that post-transcriptional RNAm odifications modulate the catalytic activity of DNAi nvarious intricate ways.

The Origins and Roles of Methylthiolated Cytokinins: Evidence From Among Life Kingdoms

“…Production of CKs through tRNA degradation is localized mainly in the cytosol. Generally, tRNA modifications contribute to an increased adaptation to environmental conditions through the control of translational efficiency and fidelity, in addition to reading frame maintenance ( Dabravolski, 2020 ; Liaqat et al, 2020 ). Following the degradation of the modified tRNA molecules, c Z-type CKs are produced.…”

RNA‐Cleaving Deoxyribozymes Differentiate Methylated Cytidine Isomers in RNA

“… [4a] The bulkier and more hydrophobic N 6 ‐isopentenyladenosine (i 6 A) in the RNA had a much stronger activating effect on deoxyribozyme‐catalyzed RNA cleavage, leading up to 2500‐fold faster cleavage of the i 6 A‐modified versus unmodified RNA substrate. [4b] …”

RNA‐Cleaving Deoxyribozymes Differentiate Methylated Cytidine Isomers in RNA

“…We found that DNA enzymes activated by m 6 A reached 5–10‐fold faster cleavage rates for modified vs. unmodified substrate [4a] . The bulkier and more hydrophobic N 6 ‐isopentenyladenosine (i 6 A) in the RNA had a much stronger activating effect on deoxyribozyme‐catalyzed RNA cleavage, leading up to 2500‐fold faster cleavage of the i 6 A‐modified versus unmodified RNA substrate [4b] …”