Dihydrouridine

Dihydrouridine

Names
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	5627-05-4 Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	85115 N
PubChem CID	94312
UNII	0D5FR359JO N
InChI InChI=1S/C9H14N2O6/c12-3-4-6(14)7(15)8(17-4)11-2-1-5(13)10-9(11)16/h4,6-8,12,14-15H,1-3H2,(H,10,13,16)/t4-,6-,7-,8-/m1/s1 N Key: ZPTBLXKRQACLCR-XVFCMESISA-N N InChI=1/C9H14N2O6/c12-3-4-6(14)7(15)8(17-4)11-2-1-5(13)10-9(11)16/h4,6-8,12,14-15H,1-3H2,(H,10,13,16)/t4-,6-,7-,8-/m1/s1 Key: ZPTBLXKRQACLCR-XVFCMESIBI
SMILES C1CN(C(=O)NC1=O)[C@H]2[C@@H]([C@@H]([C@H](O2)CO)O)O O=C1N(CCC(=O)N1)[C@@H]2O[C@@H]([C@@H](O)[C@H]2O)CO
Properties
Chemical formula	C9H14N2O6
Molar mass	246.217 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Dihydrouridine (abbreviated as D, DHU, or UH₂) 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 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, 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.

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.