Phosphoribosylanthranilate isomerase

In enzymology, a phosphoribosylanthranilate isomerase is an enzyme that catalyzes the chemical reaction


 * N-(5-phospho-beta-D-ribosyl)anthranilate $$\rightleftharpoons$$ 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate

Hence, this enzyme has one substrate, N-(5-phospho-beta-D-ribosyl)anthranilate, and one product, 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate.

This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting aldoses and ketoses. The systematic name of this enzyme class is N-(5-phospho-beta-D-ribosyl)anthranilate aldose-ketose-isomerase. Other names in common use include PRA isomerase, PRAI, IGPS:PRAI (indole-3-glycerol-phosphate, synthetase/N-5'-phosphoribosylanthranilate isomerase complex), and N-(5-phospho-beta-D-ribosyl)anthranilate ketol-isomerase. This enzyme participates in phenylalanine, tyrosine and tryptophan biosynthesis.

Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes, , , , and.