Phosphoribosyl-N-formylglycineamide

Phosphoribosyl-N-formylglycineamide (or FormylGlycinAmideRibotide, FGAR) 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] The vitamins thiamine^[3] and cobalamin^[4] also contain fragments derived from FGAR.^[5]

Phosphoribosyl-N-formylglycineamide

Names
IUPAC name (1R)-1,4-Anhydro-1-(N2-formylglycinamido)-D-ribitol 5-(dihydrogen phosphate)
Systematic IUPAC name [(2R,3S,4R,5R)-5-(2-Formamidoacetamido)-3,4-dihydroxyoxolan-2-yl]methyl dihydrogen phosphate
Other names Formylglycinamide ribonucleotide, Formylglycinamide ribotide, FGAR
Identifiers
CAS Number	349-34-8 Y
3D model (JSmol)	Interactive image
ChemSpider	115687 Y
MeSH	Phosphoribosyl-N-formylglycineamide
PubChem CID	130805
CompTox Dashboard (EPA)	DTXSID00956376
InChI InChI=1S/C8H15N2O9P/c11-3-9-1-5(12)10-8-7(14)6(13)4(19-8)2-18-20(15,16)17/h3-4,6-8,13-14H,1-2H2,(H,9,11)(H,10,12)(H2,15,16,17)/t4-,6-,7-,8-/m1/s1 Y Key: VDXLUNDMVKSKHO-XVFCMESISA-N Y
SMILES C([C@@H]1[C@H]([C@H]([C@@H](O1)NC(=O)CNC=O)O)O)OP(=O)(O)O
Properties
Chemical formula	C8H15N2O9P
Molar mass	314.187 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

FGAR is formed when the enzyme phosphoribosylglycinamide formyltransferase adds a formyl group from 10-formyltetrahydrofolate to glycineamide ribonucleotide (GAR) in reaction EC 2.1.2.2:^[6]

GAR + 10-formyltetrahydrofolate → FGAR + tetrahydrofolate

The biosynthesis pathway next converts FGAR to an amidine by the action of phosphoribosylformylglycinamidine synthase (EC 6.3.5.3), transferring an amino group from glutamine and giving 5'-phosphoribosylformylglycinamidine (FGAM) in a reaction that also requires ATP:^[6]

FGAR + ATP + glutamine + H₂O → FGAM + ADP + glutamate + Pi

See also

• 5-Aminoimidazole ribotide
• Purine metabolism