Urease
3D model of urease from Klebsiella aerogenes, two Ni2+-ions are shown as green spheres. | |||||||||
| Identifiers | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| EC no. | 3.5.1.5 | ||||||||
| CAS no. | 9002-13-5 | ||||||||
| 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 | ||||||||
| |||||||||
Ureases (EC 3.5.1.5), functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous Bacteria, Archaea, fungi, algae, plants, and some invertebrates. Ureases are nickel-containing metalloenzymes of high molecular weight. Ureases are distinct from Urecases are important in degrading avian faecal matter, which is rich in uric acid, the breakdown product of which is urea, which is then degraded by urease as described here.
These enzymes catalyze the hydrolysis of urea into carbon dioxide and ammonia:
- (NH2)2CO + H2O CO2 + 2NH3
The hydrolysis of urea occurs in two stages. In the first stage, ammonia and carbamic acid are produced. The carbamate spontaneously and rapidly hydrolyzes to ammonia and carbonic acid. Urease activity increases the pH of its environment as ammonia is produced, which is basic.