IUBMB Enzyme Nomenclature


Accepted name: phosphoribosylanthranilate isomerase

Reaction: N-(5-phospho-β-D-ribosyl)anthranilate = 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate

For diagram click here.

Other name(s): PRA isomerase; PRAI; IGPS:PRAI (indole-3-glycerol-phosphate synthetase/N-5'-phosphoribosylanthranilate isomerase complex); N-(5-phospho-β-D-ribosyl)anthranilate ketol-isomerase

Systematic name: N-(5-phospho-β-D-ribosyl)anthranilate aldose-ketose-isomerase

Comments: 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: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37259-82-8


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 (1988) 7868-7875. [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 (1970) 365-380.

3. Hütter, R., Niederberger, P. and DeMoss, J.A. Tryptophan biosynthetic genes in eukaryotic microorganisms. Annu. Rev. Microbiol. 40 (1986) 55-77.

[EC created 1990]

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