Indole-3-glycerol phosphate synthase (IPR013798)

Short name: Indole-3-glycerol_P_synth

Overlapping homologous superfamilies

Domain relationships



Indole-3-glycerol phosphate synthase (EC: (IGPS) catalyses the fourth step in the biosynthesis of tryptophan, the ring closure of 1-(2-carboxy-phenylamino)-1-deoxyribulose into indol-3-glycerol-phosphate. In some bacteria, IGPS is a single chain enzyme. In others, such as Escherichia coli, it is the N-terminal domain of a bifunctional enzyme that also catalyses N-(5'-phosphoribosyl)anthranilate isomerase (EC: (PRAI) activity (see IPR001240), the third step of tryptophan biosynthesis. In fungi, IGPS is the central domain of a trifunctional enzyme that contains a PRAI C-terminal domain and a glutamine amidotransferase (EC:2.4.2) (GATase) N-terminal domain.

A structure of the IGPS domain of the bifunctional enzyme from the mesophilic bacterium E. coli (eIGPS) has been compared with the monomeric indole-3-glycerol phosphate synthase from the hyperthermophilic archaeon Sulfolobus solfataricus (sIGPS). Both are single-domain (beta/alpha)8 barrel proteins, with one (eIGPS) or two (sIGPS) additional helices inserted before the first beta strand [PMID: 8747452].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004425 indole-3-glycerol-phosphate synthase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.