Methenyltetrahydrofolate cyclohydrolase

In enzymology, a methenyltetrahydrofolate cyclohydrolase (EC 3.5.4.9) is an enzyme that catalyzes the chemical reaction

5,10-methenyltetrahydrofolate + H₂O 10-formyltetrahydrofolate

Thus, the two substrates of this enzyme are 5,10-methenyltetrahydrofolate and H₂O, whereas its product is 10-formyltetrahydrofolate.

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 5,10-methenyltetrahydrofolate 5-hydrolase (decyclizing). Other names in common use include Citrovorum factor cyclodehydrase, cyclohydrolase, and formyl-methenyl-methylenetetrahydrofolate synthetase (combined). This enzyme participates in glyoxylate and dicarboxylate metabolism and one carbon pool by folate.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 1A4I, 1DIA, 1DIB, 1DIG, 2C2X, and 2C2Y.

References

• Rabinowitz JC and Pricer WE (1956). "The enzymatic synthesis of N10-formyltetrahydrofolic acid and its role in ATP formation during formiminoglycine degradation". J. Am. Chem. Soc. 78 (16): 4176–4178. doi:10.1021/ja01597a094. 
• Tabor H and Wyngarden L (1959). "The enzymatic formation of formiminotetrahydrofolic acid, 5,10-methenyltetrahydrofolic acid, and 10-formyltetrahydrofolic acid in the metabolism of formiminoglutamic acid". J. Biol. Chem. 234 (7): 1830–1849. PMID 13672973. 

This hydrolase article is a stub. You can help Wikipedia by expanding it.v · d · e