EC - Formate—phosphoribosylaminoimidazolecarboxamide ligase

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IntEnz Enzyme Nomenclature


Accepted name:
formate—phosphoribosylaminoimidazolecarboxamide ligase
Other names:
5-formaminoimidazole-4-carboxamide ribonucleotide synthetase
5-formaminoimidazole-4-carboxamide-1-β-D-ribofuranosyl 5'-monophosphate synthetase
purP (gene name)
Systematic name:
formate:5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide ligase (ADP-forming)



This archaeal enzyme, characterized from the methanogen Methanocaldococcus jannaschii, catalyses a step in the synthesis of purine nucleotides. It differs from the orthologous bacterial/eukaryotic enzymes, which utilize 10-formyltetrahydrofolate rather than formate and ATP. cf. EC, phosphoribosylaminoimidazolecarboxamide formyltransferase.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (37) [show] [UniProt]


  1. Ownby, K., Xu, H., White, R. H.
    A Methanocaldococcus jannaschii archaeal signature gene encodes for a 5-formaminoimidazole-4-carboxamide-1-beta-D-ribofuranosyl 5'-monophosphate synthetase. A new enzyme in purine biosynthesis.
    J. Biol. Chem. 280: 10881-10887 (2005). [PMID: 15623504]
  2. Zhang, Y., White, R. H., Ealick, S. E.
    Crystal structure and function of 5-formaminoimidazole-4-carboxamide ribonucleotide synthetase from Methanocaldococcus jannaschii.
    Biochemistry 47: 205-217 (2008). [PMID: 18069798]

[EC created 2013]