Queuosine

Queuosine
Names
	IUPAC name 7-({[(1S,4S,5R)-4,5-Dihydroxycyclopent-2-en-1-yl]amino}methyl)-7-carbaguanosine
	Systematic IUPAC name 2-Amino-5-({[(1S,4S,5R)-4,5-dihydroxycyclopent-2-en-1-yl]amino}methyl)-7-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one
Identifiers
CAS Number	57072-36-3 ;
3D model (JSmol)	Interactive image;
ChemSpider	38409 ;
PubChem CID	42119;
CompTox Dashboard (EPA)	DTXSID50205684 ;
	InChI InChI=1S/C17H23N5O7/c18-17-20-14-10(15(28)21-17)6(3-19-7-1-2-8(24)11(7)25)4-22(14)16-13(27)12(26)9(5-23)29-16/h1-2,4,7-9,11-13,16,19,23-27H,3,5H2,(H3,18,20,21,28)/t7-,8-,9+,11+,12+,13+,16+/m0/s1 Key: QQXQGKSPIMGUIZ-AEZJAUAXSA-N ; InChI=1/C17H23N5O7/c18-17-20-14-10(15(28)21-17)6(3-19-7-1-2-8(24)11(7)25)4-22(14)16-13(27)12(26)9(5-23)29-16/h1-2,4,7-9,11-13,16,19,23-27H,3,5H2,(H3,18,20,21,28)/t7-,8-,9+,11+,12+,13+,16+/m0/s1 Key: QQXQGKSPIMGUIZ-AEZJAUAXBO;
	SMILES C1=C[C@@H]([C@@H]([C@H]1NCC2=CN(C3=C2C(=O)N=C(N3)N)[C@H]4[C@@H]([C@@H]([C@H](O4)CO)O)O)O)O;
Properties
Chemical formula	C17H23N5O7
Molar mass	409.399 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Queuosine is a modified nucleoside that is present in certain tRNAs in bacteria and eukaryotes. It contains the nucleobase queuine. Originally identified in E. coli, queuosine was found to occupy the first anticodon position of tRNAs for histidine, aspartic acid, asparagine and tyrosine. The first anticodon position pairs with the third "wobble" position in codons, and queuosine improves accuracy of translation compared to guanosine. Synthesis of queuosine begins with GTP. In bacteria, three structurally unrelated classes of riboswitch are known to regulate genes that are involved in the synthesis or transport of pre-queuosine₁, a precursor to queuosine: PreQ1-I riboswitches, PreQ1-II riboswitches and PreQ1-III riboswitches.

Queuosine biosynthesis genes have also been found on phage genomes and may be involved in protection from genome degradation by the host.