Indole-3-glycerol-phosphate synthase

In enzymology, an indole-3-glycerol-phosphate synthase is an enzyme that catalyzes the chemical reaction


 * 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate $$\rightleftharpoons$$ 1-C-(indol-3-yl)-glycerol 3-phosphate + CO2 + H2O

Hence, this enzyme has one substrate, 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate, but 3 products: 1-C-(indol-3-yl)-glycerol 3-phosphate, CO2, and H2O.

This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose-5-phosphate carboxy-lyase [cyclizing 1-C-(indol-3-yl)glycerol-3-phosphate-forming]. Other names in common use include indoleglycerol phosphate synthetase, indoleglycerol phosphate synthase, indole-3-glycerophosphate synthase, 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose-5-phosphate, and carboxy-lyase (cyclizing). This enzyme participates in phenylalanine, tyrosine and tryptophan biosynthesis and two-component system - general. It employs one cofactor, pyruvate.

Structural studies
As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , and.