|PDB structures||RCSB PDB PDBe PDBsum|
|Gene Ontology||AmiGO / QuickGO|
- 5-formimidoyltetrahydrofolate 5,10-methenyltetrahydrofolate + 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 188.8.131.52), 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.
- Rabinowitz JC; Pricer WE (1956). "Formiminotetrahydrofolic acid and methenyltetrahydrofolic acid as intermediates in the formation of N10-formyltetrahydrofolic acid". J. Am. Chem. Soc. 78 (21): 5702–5704. doi:10.1021/ja01602a073.
- MacKenzie RE, Aldridge M, Paquin J (10 October 1980). "The bifunctional enzyme formiminotransferase-cyclodeaminase is a tetramer of dimers". J. Biol. Chem. 255 (19): 9474–8. PMID 7410436.
- Kohls D, Sulea T, Purisima EO, MacKenzie RE, Vrielink A (2000). "The crystal structure of the formiminotransferase domain of formiminotransferase-cyclodeaminase: implications for substrate channeling in a bifunctional enzyme". Structure. 8 (1): 35–46. doi:10.1016/S0969-2126(00)00078-2. PMID 10673422.