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We are deeply saddened by the passing of Amos Bairoch (1957–2025), the creator of PROSITE. We wish to dedicate our latest paper, published shortly before his death, to him. He will always be a source of inspiration to us.
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Amos Bairoch

PROSITE documentation PDOC00536
Indole-3-glycerol phosphate synthase signature


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PURL: https://purl.expasy.org/prosite/documentation/PDOC00536

Description

Indole-3-glycerol phosphate synthase (EC 4.1.1.48) (IGPS) catalyzes 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 catalyzes N-(5'-phosphoribosyl)anthranilate isomerase (PRAI) activity, the third step of tryptophan biosynthesis. In fungi, IGPS is the central domain of a trifunctional enzyme that also contains a PRAI C-terminal domain and a glutamine amidotransferase N-terminal domain.

The N-terminal section of IGPS contains a highly conserved region which X-ray crystallography studies [1] have shown to be part of the active site cavity. We use this region as a signature pattern for IGPS.

Last update:

April 2006 / Pattern revised.

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Technical section

PROSITE method (with tools and information) covered by this documentation:

IGPS, PS00614; Indole-3-glycerol phosphate synthase signature  (PATTERN)


Reference

1AuthorsWilmanns M. Priestle J.P. Niermann T. Jansonius J.N.
TitleThree-dimensional structure of the bifunctional enzyme phosphoribosylanthranilate isomerase: indoleglycerolphosphate synthase from Escherichia coli refined at 2.0 A resolution.
SourceJ. Mol. Biol. 223:477-507(1992).
PubMed ID1738159



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