enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a 5-formyltetrahydrofolate cyclo-ligase () is an enzyme that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the chemical reaction :ATP +

5-formyltetrahydrofolate Folinic acid, also known as leucovorin, is a medication used to decrease the toxic effects of methotrexate and pyrimethamine. It is also used in combination with 5-fluorouracil to treat colorectal cancer and pancreatic cancer, may be used to tr ...

(folinic acid)

\rightleftharpoons

ADP + phosphate +

5,10-methenyltetrahydrofolate 5,10-Methenyltetrahydrofolate (5,10-CH=THF) is a form of tetrahydrofolate that is an intermediate in metabolism. 5,10-CH=THF is a coenzyme that accepts and donates methenyl (CH=) groups. It is produced from 5,10-methylenetetrahydrofolate by eith ...

Thus, the two substrates of this enzyme are

ATP ATP may refer to: Companies and organizations * Association of Tennis Professionals, men's professional tennis governing body * American Technical Publishers, employee-owned publishing company * ', a Danish pension * Armenia Tree Project, non ...

and

, whereas its 3 products are

ADP Adp or ADP may refer to: Aviation * Aéroports de Paris, airport authority for the Parisian region in France * Aeropuertos del Perú, airport operator for airports in northern Peru * SLAF Anuradhapura, an airport in Sri Lanka * Ampara Air ...

, phosphate, and

. This enzyme belongs to the family of ligases, specifically the cyclo-ligases, which form carbon-nitrogen bonds. The systematic name of this enzyme class is 5-formyltetrahydrofolate cyclo-ligase (ADP-forming). Other names in common use include 5,10-methenyltetrahydrofolate synthetase (MTHFS), formyltetrahydrofolic cyclodehydrase, and 5-formyltetrahydrofolate cyclodehydrase. This enzyme participates in one carbon pool by folate.

Structural studies

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes , , , , and .

Role in pathology

Mutations of the MTHFS gene cause the disease

5,10-methenyltetrahydrofolate synthetase deficiency 5,10-Methenyltetrahydrofolate synthetase deficiency (MTHFS deficiency) is a rare neurodevelopmental disorder caused by mutations affecting the MTHFS gene, which encodes the enzyme 5,10-Methenyltetrahydrofolate synthetase. The disease starts at b ...

References

* EC 6.3.3 Enzymes of known structure {{6.3-enzyme-stub