Imidazoleglycerol-phosphate dehydratase
From Wikipedia, the free encyclopedia
The enzyme imidazoleglycerol-phosphate dehydratase (EC 4.2.1.19) catalyzes the chemical reaction
- D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate 3-(imidazol-4-yl)-2-oxopropyl phosphate + H2O
imidazoleglycerol-phosphate dehydratase | |||||||||
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Identifiers | |||||||||
EC no. | 4.2.1.19 | ||||||||
CAS no. | 9024-35-5 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
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Imidazoleglycerol-phosphate dehydratase | |||||||||
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Identifiers | |||||||||
Symbol | IGPD | ||||||||
Pfam | PF00475 | ||||||||
Pfam clan | CL0329 | ||||||||
InterPro | IPR000807 | ||||||||
PROSITE | PDOC00738 | ||||||||
SCOP2 | 1rhy / SCOPe / SUPFAM | ||||||||
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This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is D-erythro-1-(imidazol-4-yl)glycerol-3-phosphate hydro-lyase [3-(imidazol-4-yl)-2-oxopropyl-phosphate-forming]. Other names in common use include IGP dehydratase, and D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate hydro-lyase. This enzyme participates in histidine metabolism as it is involved in the 6th step of histidine biosynthesis as part of a nine step cyclical pathway.
There are two isoforms of IGPD; IGPD1 and IGPD2. The different isoforms are highly conserved with only 8 amino acids differing between them. These subtle differences however affect their activity but as yet it is unknown how.
In most organisms IGPD is a monofunctional protein of about 22 to 29 kD. In some bacteria such as Escherichia coli, it is the C-terminal domain of a bifunctional protein that include a histidinol-phosphatase domain.[1] In E. coli, this is the protein encoded by the hisB gene.[2]