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CoFactor: Tetrahydrofolic acidGeneral information2D representation
Key facts
TagsMolecular functionThe cofactor has a crucial role in C1-metabolism: it transports and donates C1 (mainly methyl groups from serine hydroxymethyltransferase reaction)[1]. The C1 residue can be reduced or oxidized (methyl, methylene, formyl or methenyl) [1]. Therefore, the folate pool is a mixture of molecules, differing in the oxidation state of the pterin ring (di- or tetrahydro), the oxidation state of the C1-unit carried, and in the length of the glutamate chain. Only the tetrahydro state can transport C1 units [1]. Folate derivatives can also act as chromophores in DNA-repair[1]. Chemical propertiesThe molecule is composed of a pterin ring, a p-aminobenzoic acid and a polyglutamate chain. [1]PathwaysFolic acid cofactors are involved in purine and pyrimidine biosynthesis [1]. All pathways see fig 1 in [1]. Therefore, the synthesis of the cofactors NAD(P), FAD, CoA and SAM depend on them [1]. The purine and pyrimidine biosynthesis is similar in all organisms an requires 13 steps from ribose-5-phosphate. The C1 units from the folate cofactors become C2 and C8 of the purine ring [1]. Only bacteria, plants and lower eukaryotes (yeast, protozoa) have the complete biosynthetic pathway. The folate molecule is similar to a number of other pterin-based cofactors, like molybdopterin or flavins [3]. THF is biosynthesised in microorganisms including bacteria, in lower eukaryotes and plants, but not in animals [3]. It is synthesised from GTP, chorismate and glutamate, and there are 11 enzymes in the biosynthetic pathway [3]. CommentGreen leafy vegetables are a good food source for folate, in contrast to roots (like carrots), storage organs (like potatoes) or most fruits [1]. Folate content highly depends on food storage, processing an cooking [1]. References
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