IUBMB Enzyme Nomenclature


Accepted name: formimidoyltetrahydrofolate cyclodeaminase

Reaction: 5-formimidoyltetrahydrofolate = 5,10-methenyltetrahydrofolate + NH3

For diagram of reaction click here (another example).

Other name(s): formiminotetrahydrofolate cyclodeaminase; 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing)

Systematic name: 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing; 5,10-methenyltetrahydrofolate-forming)

Comments: In eukaroytes, occurs as a bifunctional enzyme that also has glutamate formimidoyltransferase (EC activity.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9032-05-7


1. Rabinowitz, J.C. and Pricer, W.E. Formimino-tetrahydrofolic acid and methenyltetrahydrofolic acid as intermediates in the formation of N10-formyltetrahydrofolic acid. J. Am. Chem. Soc. 78 (1956) 5702-5704.

[EC created 1961, modified 2000]

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