MSI_000056648

Dihydrouridine is a pyrimidine which is the result of adding two hydrogen atoms to a uridine. Dihydrouridine is found only in tRNA molecules. An inhibitor of nucleotide metabolism. [HMDB] Dihydrouridine (abbreviated as D,[1] DHU, or UH2) is a pyrimidine nucleoside which is the result of adding two hydrogen atoms to a uridine, making it a fully saturated pyrimidine ring with no remaining double bonds. D is found in tRNA and rRNA molecules as a nucleoside; the corresponding nucleobase is 5,6-dihydrouracil. Because it is non-planar, D disturbs the stacking interactions in helices and destabilizes the RNA structure. D also stabilizes the C2’-endo sugar conformation, which is more flexible than the C3’-endo conformation; this effect is propagated to the 5’-neighboring residue. Thus, while pseudouridine and 2’-O-methylations stabilize the local RNA structure, D does the opposite.[2] The tRNAs of organisms that grow at low temperatures (psychrophiles) have high 5,6-dihydrouridine levels (40-70\\\% more on average) which provides the necessary local flexibility of the tRNA at or below the freezing point.[3] Dihydrouridine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=5627-05-4 (retrieved 2024-07-01) (CAS RN: 5627-05-4). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). 5,6-Dihydrouridine is a modified base found in conserved positions in the D-loop of tRNA in Bacteria, Eukaryota, and some Archaea. 5,6-Dihydrouridine is a modified base found in conserved positions in the D-loop of tRNA in Bacteria, Eukaryota, and some Archaea.