CATH Classification
| Level | CATH Code | Description | 
|---|---|---|
|   | 3 | Alpha Beta | 
|   | 3.20 | Alpha-Beta Barrel | 
|   | 3.20.20 | TIM Barrel | 
|   | 3.20.20.70 | Aldolase class I | 
Domain Context
CATH Clusters
| Superfamily | Aldolase class I | 
| Functional Family | Imidazole glycerol phosphate synthase subunit HisF | 
Enzyme Information
| 4.3.2.10 | Imidazole glycerol-phosphate synthase. based on mapping to UniProt Q7SIB9 5-((5-phospho-1-deoxy-D-ribulos-1-ylamino)methylideneamino)-1-(5-phospho- beta-D-ribosyl)imidazole-4-carboxamide + L-glutamine = 5-amino-1- (5-phospho-beta-D-ribosyl)imidazole-4-carboxamide + D-erythro-1- (imidazol-4-yl)glycerol 3-phosphate + L-glutamate. -!- The enzyme is involved in histidine biosynthesis, as well as purine nucleotide biosynthesis. -!- The enzymes from archaea and bacteria are heterodimeric. -!- A glutaminase component (cf. EC 3.5.1.2) produces an ammonia molecule that is transferred by a 25 A tunnel to a cyclase component, which adds it to the imidazole ring, leading to lysis of the molecule and cyclization of one of the products. -!- The glutminase subunit is only active within the dimeric complex. -!- In fungi and plants the two subunits are combined into a single polypeptide. | 
UniProtKB Entries (1)
| Q7SIC0 | HIS5_THET8 Thermus thermophilus HB8 Imidazole glycerol phosphate synthase subunit HisH | 
PDB Structure
| PDB | 1KA9 | 
| External Links | |
| Method | X-RAY DIFFRACTION | 
| Organism | Escherichia | 
| Primary Citation | Structure of imidazole glycerol phosphate synthase from Thermus thermophilus HB8: open-closed conformational change and ammonia tunneling. J.Biochem. | 
