6533b7ddfe1ef96bd1274a4a
RESEARCH PRODUCT
The RNA methyltransferase Dnmt2 methylates DNA in the structural context of a tRNA
Steffen KaiserStefanie KellnerAlbert JeltschTomasz P. JurkowskiDirk SchneiderMark Helmsubject
0301 basic medicineRNA methylationBiologyMethylationCytosineMiceStructure-Activity Relationship03 medical and health scienceschemistry.chemical_compoundRNA Transferenzyme kineticsAnimalsHumansDNA (Cytosine-5-)-MethyltransferasesGuide RNA5-methylcytosinetRNAMolecular Biologymodification pathway crosstalkTRNA methylationRNADNACell BiologyMethylationDNA MethylationRNA modification5-Methylcytosine030104 developmental biologyBiochemistrychemistryTransfer RNARNA methylationNucleic Acid ConformationDnmt2DNAResearch Paperdescription
The amino acid sequence of Dnmt2 is very similar to the catalytic domains of bacterial and eukaryotic DNA-(cytosine 5)-methyltransferases, but it efficiently catalyzes tRNA methylation, while its DNA methyltransferase activity is the subject of controversial reports with rates varying between zero and very weak. By using composite nucleic acid molecules as substrates, we surprisingly found that DNA fragments, when presented as covalent DNA-RNA hybrids in the structural context of a tRNA, can be more efficiently methylated than the corresponding natural tRNA substrate. Furthermore, by stepwise development of tRNAAsp, we showed that this natural Dnmt2 substrate could be engineered to employ RNAs that act like guide RNAs in vitro. The 5’-half of tRNAAsp was able to efficiently guide methylation toward a single stranded tRNA fragment as would result from tRNA cleavage by tRNA specific nucleases. In a more artificial setting, a composite system of guide RNAs could ultimately be engineered to enable the enzyme to perform cytidine methylation on single stranded DNA in vitro.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-01-01 |