Glycineamide ribonucleotide

Glycinamide ribonucleotide (or GAR) is a biochemical intermediate in the formation of purine nucleotides via inosine-5-monophosphate, and hence is a building block for DNA and RNA.^[1][2][3] The vitamins thiamine^[4] and cobalamin^[5] also contain fragments derived from GAR.^[6]

Phosphoribosylamine (PRA)

Glycineamide ribonucleotide

Names
IUPAC name (1R)-1,4-Anhydro-1-glycinamido-D-ribitol 5-(dihydrogen phosphate)
Systematic IUPAC name [(2R,3S,4R,5R)-5-(2-Aminoacetamido)-3,4-dihydroxyoxolan-2-yl]methyl dihydrogen phosphate
Other names Glycinamide ribotide, GAR
Identifiers
CAS Number	10074-18-7 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:143019
ChemSpider	141370 Y
KEGG	C03838 Y
PubChem CID	160913
UNII	K343GZ6PUY Y
CompTox Dashboard (EPA)	DTXSID70143478
InChI InChI=1S/C7H15N2O8P/c8-1-4(10)9-7-6(12)5(11)3(17-7)2-16-18(13,14)15/h3,5-7,11-12H,1-2,8H2,(H,9,10)(H2,13,14,15)/t3-,5-,6-,7-/m1/s1 Y Key: OBQMLSFOUZUIOB-SHUUEZRQSA-N Y
SMILES C([C@@H]1[C@H]([C@H]([C@@H](O1)NC(=O)CN)O)O)OP(=O)(O)O
Properties
Chemical formula	C7H15N2O8P
Molar mass	286.177 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

GAR is the product of the enzyme phosphoribosylamine—glycine ligase acting on phosphoribosylamine (PRA) to combine it with glycine in a process driven by ATP. The reaction, EC 6.3.4.13 forms an amide bond:^[7]

PRA + glycine + ATP → GAR + ADP + Pi

The biosynthesis pathway next adds a formyl group from 10-formyltetrahydrofolate to GAR, catalysed by phosphoribosylglycinamide formyltransferase in reaction EC 2.1.2.2 and producing formylglycinamide ribotide (FGAR):^[7]

GAR + 10-formyltetrahydrofolate → FGAR + tetrahydrofolate

See also

• 5-Aminoimidazole ribotide
• Purine metabolism