Formimidoyltetrahydrofolate cyclodeaminase
| formimidoyltetrahydrofolate cyclodeaminase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 4.3.1.4 | ||||||||
| CAS no. | 9032-05-7 | ||||||||
| 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 | ||||||||
| |||||||||
In enzymology, a formimidoyltetrahydrofolate cyclodeaminase (EC 4.3.1.4) is an enzyme that catalyzes the chemical reaction
- 5-formimidoyltetrahydrofolate 5,10-methenyltetrahydrofolate + NH3
Hence, this enzyme has one substrate, 5-formimidoyltetrahydrofolate, and two products, 5,10-methenyltetrahydrofolate and NH3.
This enzyme belongs to the family of lyases, specifically ammonia lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing 5,10-methenyltetrahydrofolate-forming). Other names in common use include formiminotetrahydrofolate cyclodeaminase, and 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing). This enzyme participates in folate metabolism by catabolising histidine and adding to the C1-tetrahydrofolate pool.
In mammals, this enzyme can be found as part of a bifunctional enzyme in a single polypeptide with glutamate formimidoyltransferase (EC 2.1.2.5), the enzyme activity that catalyses the previous step in the histidine catabolic pathway. This arrangement allows the 5-formimidoyltetrahydrofolate intermediate to move directly from one active site to another without being released into solution, in a process called substrate channeling.