### (10-Formyltetrahydrofolate (10-CHO-THF) ) ده-فورمیل تتراهیدروفولات

.10-Formyltetrahydrofolate (10-CHO-THF
10- فورمیل تتراهیدروفولات
is a form of tetrahydrofolate that acts as a donor of formyl groups in anabolism. In these reactions 10-CHO-THF is used as a substrate in formyltransferase reactions. This is important in purine biosynthesis, where 10-CHO-THF is a substrate for phosphoribosylaminoimidazolecarboxamide formyltransferase, as well as in the formylation of the methionyl initiator tRNA (fMet-tRNA), when 10-CHO-THF is a substrate for methionyl-tRNA formyltransferase.

## Biosynthesis

10-CHO-THF is produced either by the enzyme methenyltetrahydrofolate cyclohydrolase via the reaction
5,10-methenyltetrahydrofolate + H2 10-formyltetrahydrofolate
or by the enzyme formate-tetrahydrofolate ligase via the reaction
ATP + formate + tetrahydrofolate  ADP + phosphate + 10-formyltetrahydrofolate
It can be converted back into tetrahydrofolate (THF) by formyltetrahydrofolate dehydrogenase or THF and formate by formyltetrahydrofolate deformylase.