Английская Википедия:10-Formyltetrahydrofolate

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10-Formyltetrahydrofolate (10-CHO-THF) 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.


Functions

Two equivalents of 10-CHO-THF are required in purine biosynthesis through the pentose phosphate pathway, where 10-CHO-THF is a substrate for phosphoribosylaminoimidazolecarboxamide formyltransferase.

10-CHO-THF is required for the formylation of methionyl-tRNA formyltransferase to give fMet-tRNA.[1]

Formation from methenyltetrahydrofolate

10-CHO-THF is produced from methylenetetrahydrofolate (CH2H4F) via a two step process. The first step generates 5,10-methenyltetrahydrofolate:[2]

CH2H4F + NAD+ <math>\rightleftharpoons</math> CH2H2F + NADH + H+

In the second step 5,10-methenyltetrahydrofolate undergoes hydrolysis:

CH2H2F + H2O <math>\rightleftharpoons</math> CHO-H4F +

The latter is equivalently written:

5,10-methenyltetrahydrofolate + H2O <math>\rightleftharpoons</math> 10-formyltetrahydrofolate

10-CHO-THF is also produced by the reaction

ATP + formate + tetrahydrofolate <math>\rightleftharpoons</math> ADP + phosphate + 10-formyltetrahydrofolate

This reaction is catalyzed by formate-tetrahydrofolate ligase.

It can be converted back into tetrahydrofolate (THF) by formyltetrahydrofolate dehydrogenase or THF and formate by formyltetrahydrofolate deformylase.

References

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