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spinqualitylabelsall models 1rhy, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of Imidazole Glycerol Phosphate Dehydratase

Overview

Imidazole glycerol-phosphate dehydratase (IGPD) catalyzes the sixth step, of histidine biosynthesis. The enzyme is of fundamental biochemical, interest, because it catalyzes removal of a non-acidic hydrogen atom in, the dehydration reaction. It is also a potential target for development of, herbicides. IGPD is a metalloenzyme in which transition metals induce, aggregation and are required for catalysis. Addition of 1 equivalent of, Mn(2+)/subunit is shown by analytical ultracentrifugation to induce the, formation of 24-mers from trimeric IGPD. Two histidine-rich motifs may, participate in metal binding and aggregation. The 2.3-A crystal structure, of metal-free trimeric IGPD from the fungus Filobasidiella neoformans, reveals a novel fold containing an internal repeat, apparently the result, of gene duplication. The 95-residue alpha/beta half-domain occurs in a few, other proteins, including the GHMP kinase superfamily, (galacto-homoserine-mevalonate-phosphomevalonate), but duplication to form, a compact domain has not been seen elsewhere. Conserved residues cluster, at two types of sites in the trimer, each site containing a conserved, histidine-rich motif. A model is proposed for the intact, active 24-mer in, which all highly conserved residues, including the histidine-rich motifs, in both the N- and C-terminal halves of the polypeptide, cluster at a, common site between trimers. This site is a candidate for the active site, and also for metal binding leading to aggregation of trimers. The, structure provides a basis for further studies of enzyme function and, mechanism and for development of more potent and specific herbicides.

About this Structure

1RHY is a Single protein structure of sequence from Filobasidiella neoformans with HG, EMC, SO4, ACY and GOL as ligands. Active as Imidazoleglycerol-phosphate dehydratase, with EC number 4.2.1.19 Full crystallographic information is available from OCA.

Reference

Crystal structure of imidazole glycerol-phosphate dehydratase: duplication of an unusual fold., Sinha SC, Chaudhuri BN, Burgner JW, Yakovleva G, Davisson VJ, Smith JL, J Biol Chem. 2004 Apr 9;279(15):15491-8. Epub 2004 Jan 14. PMID:14724278

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