5-formyltetrahydrofolate cyclo-ligase (MTHFS)

Contributes to tetrahydrofolate metabolism. Helps regulate carbon flow through the folate-dependent one-carbon metabolic network that provides carbon for the biosynthesis of purines, thymidine and amino acids.

Catalyzes the irreversible conversion of 5-formyltetrahydrofolate (5-FTHF) to yield 5,10- methenyltetrahydrofolate. .