In enzymology, a GTP cyclohydrolase II (EC 3.5.4.25) is an enzyme that catalyzes the chemical reaction
| GTP cyclohydrolase II | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 3.5.4.25 | ||||||||
| CAS no. | 56214-35-8 | ||||||||
| 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 | ||||||||
| |||||||||
- GTP + 3 H2O formate + 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + diphosphate
Thus, the two substrates of this enzyme are GTP and H2O, whereas its 3 products are formate, 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine, and diphosphate.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is GTP 7,8-8,9-dihydrolase (diphosphate-forming). Other names in common use include guanosine triphosphate cyclohydrolase II, and GTP-8-formylhydrolase. This enzyme participates in riboflavin metabolism.
Structural studies edit
As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 2BZ0 and 2BZ1.
References edit
- Foor F, Brown GM (1975). "Purification and properties of guanosine triphosphate cyclohydrolase II from Escherichia coli". J. Biol. Chem. 250 (9): 3545–51. PMID 235552.
