37 - Biochemical reactions of Folate coenzymes

Reaction	Coenzyme Form of Folate Involved and Single Carbon unit transferred	Importance
Formate activation	THF; -CHO group transferred.	Generation of 10-formyl-THF
Purine synthesis
Formation of glycinamide ribonucleotide	5,10-MethyleneTHF; -CHO group transferred	Formation of purines needed for DNA, RNA synthesis, but reactions  probably not rate limiting
Formylation of aminoimidazolecarboxamide-ribonucleotide (AICAR)	10-Formyl (CHO)THF;-CHO group transferred
Pyrimidine synthesis
Methylation of deoxyuridine monophosphate (dUMP) to thymidine monophosphate (dTMP)	5,10-MethyleneTHF;-CH3 group transferred.	Rate limiting in DNA synthesis
		Oxidizes THF to DHF
		Some breakdown of folate at the C-9–N-10 bond
Amino acid interconversion
Serine–glycine interconversion	THF; =CH2 group transferred	Entry of single carbon units into active pool
Homocysteine to methionine	5-Methyl(M)THF; -CH3 group transferred	Demethylation of 5-MTHF to THF; also requires cobalamin, flavine adenine dinucleotide, ATP, and adenosyl methionine
Forminoglutamic acid to glutamic acid in histidine catabolism	THF; -HN-CH= group transferred