Formate 10-formyltetrahydrofolate synthetase

These three compounds exert many similar effects in nucleotide metabolism of chicks and rats [167]. They cause an increase of the liver RNA content and of the nucleotide content of the acid-soluble fraction in chicks [168], as well as an increase in rate of turnover of these polynucleotide structures [169,170]. Further experiments in chicks indicate that orotic acid, vitamin B12 and methionine exert a certain action on the activity of liver deoxyribonuclease, but have no effect on ribonuclease. Their effect is believed to be on the biosynthetic process rather than on catabolism [171]. Both orotic acid and vitamin Bu increase the levels of dihydrofolate reductase (EC 1.5.1.4), formyltetrahydrofolate synthetase and serine hydroxymethyl transferase in the chicken liver when added in diet. It is believed that orotic acid may act directly on the enzymes involved in the synthesis and interconversion of one-carbon folic acid derivatives [172]. The protein incorporation of serine, but not of leucine or methionine, is increased in the presence of either orotic acid or vitamin B12 [173]. In addition, these two compounds also exert a similar effect on the increased formate incorporation into the RNA of liver cell fractions in chicks [174—176]. It is therefore postulated that there may be a common role of orotic acid and vitamin Bj2 at the level of the transcription process in m-RNA biosynthesis [174—176]. 

Chloro-9-cyclopentyl-8-azapurine inhibited synthesis of DNA, RNA, and protein in E. coli. Blockage of thymine-nucleotide formation was the first effect seen. Alkylation of enzymes by the 6-chloro substituent was suggested as a mechanism. This azapurine inhibited the RNA polymerase from E. coli, but not that from M. lysodeikticus. Formyltetrahydrofolate synthetases, of both mammalian and bacterial origins, were strongly inhibited. The same azapurine, at 0.3 mM, markedly inhibited the steroid-induced synthesis of A -3-ketosteroid isomerase in Pseudomonas testoster-oni ... 

Scheme 1.—The Reactions Involved in the Enzymic Determination of (a) Glycerol, (b) Erythritol, (c) Glycolaldehyde, and (d) and (e) Formic Acid. [Abbreviations ATP, adenosine 5 -triphosphate ADP, adenosine S -pyrophosphate NAD and NADH, the oxidized and reduced forms of nicotinamide adenine dinucleotide PEP, enolpyruvate phosphate Pi, inorganic orthophosphate GK, glycerol kinase GDH, u-glycerophosphate dehydrogenase EK, erythritol kinase PK, pyruvate kinase YAD, yeast alcohol dehydrogenase FS, formyltetrahydrofolate synthetase FD, formate dehydrogenase and NR, nitrate reductase.]...

N -Formyltetrahydrofolate is formed by the condensation of THFA with formate in the presence of ATP. Formyltetrahydrofolate synthetase has been found in bacteria and in mammalian tissues. The erythrocyte enzyme has been partially purified. 

As noted previously, linear gramicidin" " and anabaenopeptilid" synthetases begin with modules containing formylation (F) domains in an F-A-PCP initiation module. In vitro experiments have revealed that formylation domains act upon aminoacyl-S-PCP intermediates before amide bond formation occurs within the downstream C domain. These F domains likely utilize w °-formyltetrahydrofolate as a cofactor. ... 

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