Dihydrouridine

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Dihydrouridine
Image:Dihydrouridine.png
IUPAC name 1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,3-diazinane-2,4-dione
Other names 3,4-dihydrouridine
3,4,5,6-tetrahydrouridine
5,6-dihydrouridine
Identifiers
CAS number
PubChem 94312
Properties
Molecular formula C9H14N2O6
Molar mass 246.217 g/mol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Dihydrouridine (D) is a pyrimidine 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.

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 then the C3’-endo conformation, and 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. [1]

tRNA 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.[2]


[edit] References

  1. ^ Image:Free_text.png Dalluge JJ; Hashizume T, Sopchik AE, McCloskey JA, Davis DR. (Mar 15 1996). "Conformational flexibility in RNA: the role of dihydrouridine". Nucleic Acids Res 24(6): 1073-9. PMID 8604341. 
  2. ^ Image:Free_text.png Dalluge JJ; Hamamoto T, Horikoshi K, Morita RY, Stetter KO, and McCloskey JA (Mar 1997). "Posttranscriptional modification of tRNA in psychrophilic bacteria". J Bacteriol 179(6): 1918-23. PMID 9068636.