EC - Phosphoribosylanthranilate isomerase

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IntEnz Enzyme Nomenclature


Accepted name:
phosphoribosylanthranilate isomerase
Other names:
N-(5-phospho-β-D-ribosyl)anthranilate ketol-isomerase
IGPS:PRAI (indole-3-glycerol-phosphate synthetase/N-5'-phosphoribosylanthranilate isomerase complex)
PRA isomerase
N-(5'-phosphoribosyl)anthranilate isomerase
Systematic name:
N-(5-phospho-β-D-ribosyl)anthranilate aldose-ketose-isomerase



In some organisms, this enzyme is part of a multifunctional protein, together with one or more other components of the system for the biosynthesis of tryptophan [EC (anthranilate phosphoribosyltransferase), EC (indole-3-glycerol-phosphate synthase), EC (anthranilate synthase) and EC (tryptophan synthase)].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004640
UniProtKB/Swiss-Prot: (366) [show] [UniProt]


  1. Braus, G.H., Luger, K., Paravicini, G., Schmidheini, T., Kirschner, K. and Hütter, R.
    The role of the TRP1 gene in yeast tryptophan biosynthesis.
    J. Biol. Chem. 263: 7868-7875 (1988). [PMID: 3286643]
  2. Creighton, T.E. and Yanofsky, C.
    Chorismate to tryptophan (Escherichia coli) - anthranilate synthetase, PR transferase, PRA isomerase, InGP synthetase, tryptophan synthetase.
    Methods Enzymol. 17A: 365-380 (1970).
  3. Hütter, R., Niederberger, P. and DeMoss, J.A.
    Tryptophan biosynthetic genes in eukaryotic microorganisms.
    Annu. Rev. Microbiol. 40: 55-77 (1986).

[EC created 1990]