Cytosolic PFAS (phosphoribosylformylglycinamidine synthase) catalyzes the reaction of 5'-phosphoribosylformylglycinamide (FGAR), L-glutamine, ATP, and water to form 5'-phosphoribosylformylglycinamidine (FGAM), L-glutamate, ADP, and orthophosphate. The enzyme has been purified to homogeneity from chicken liver and characterized biochemically, but its amino acid sequence remains unknown so it cannot be associated with a specific chicken gene. The enzyme is active as a monomer, though catalytically active multimers have been observed (Mizobuchi and Buchanan 1968; Frere et al. 1971).
phosphoribosylformylglycinamidine synthase activity of PFAS [cytosol]