CATH Classification
| Level | CATH Code | Description |
|---|---|---|
|
3 | Alpha Beta |
|
3.40 | 3-Layer(aba) Sandwich |
|
3.40.50 | Rossmann fold |
|
3.40.50.880 | Class I glutamine amidotransferase (GATase) domain |
Domain Context
CATH Clusters
| Superfamily | 3.40.50.880 |
| Functional Family | Imidazole glycerol phosphate synthase hisHF |
Enzyme Information
| 4.3.2.10 |
Imidazole glycerol-phosphate synthase.
based on mapping to UniProt P33734
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.
|
| 3.5.1.2 |
Glutaminase.
based on mapping to UniProt P33734
L-glutamine + H(2)O = L-glutamate + NH(3).
|
UniProtKB Entries (1)
| P33734 |
HIS5_YEAST
Saccharomyces cerevisiae S288C
Imidazole glycerol phosphate synthase hisHF
|
PDB Structure
| PDB | 1OX4 |
| External Links | |
| Method | X-RAY DIFFRACTION |
| Organism | Escherichia |
| Primary Citation |
Towards Understanding the Mechanism of the Complex Cyclization Reaction
Catalyzed by Imidazole Glycerophosphate Synthase: Crystal Structures of a Ternary Complex and the Free
Enzyme
Biochemistry
|