InterPro domain: IPR041729

Formyl-FH4 Hydrolase catalyzes the hydrolysis of 10-formyltetrahydrofolate (formyl-FH4) to FH4 and formate. Formate is the substrate of phosphoribosylglycinamide transformylase for step three of de novo purine nucleotide synthesis. Formyl-FH4 hydrolase has been proposed to regulate the balance of FH4 and C1-FH4 in the cell. The enzyme uses methionine and glycine to sense the pools of C1-FH4 and FH4, respectively [ 1 ].

Proteins containing this domain include PurU [ 2 ]. It has an N-terminal ACT domain, which is commonly involved in specifically bind an amino acid or other small ligand leading to regulation of the enzyme. The N terminus of these proteins may be responsible for the binding of the regulators methionine and glycine.

1. Formyltetrahydrofolate hydrolase, a regulatory enzyme that functions to balance pools of tetrahydrofolate and one-carbon tetrahydrofolate adducts in Escherichia coli. J. Bacteriol. 177, 1292-8
2. purU, a source of formate for purT-dependent phosphoribosyl-N-formylglycinamide synthesis. J. Bacteriol. 175, 7066-73