cd00477

Formyltetrahydrofolate synthetase (FTHFS) catalyzes the ATP-dependent activation of formate ion via its addition to the N10 position of tetrahydrofolate. FTHFS is a highly expressed key enzyme in both the Wood-Ljungdahl pathway of autotrophic CO2 fixation (acetogenesis) and the glycine synthase/reductase pathways of purinolysis. The key physiological role of this enzyme in acetogens is to catalyze the formylation of tetrahydrofolate, an initial step in the reduction of carbon dioxide and other one-carbon precursors to acetate. In purinolytic organisms, the enzymatic reaction is reversed, liberating formate from 10-formyltetrahydrofolate with concurrent production of ATP.