The protein encoded by this gene is a member of the purine/pyrimidine phosphoribosyltransferase family. This protein is a regulatory allosteric enzyme that catalyzes the first step of de novo purine nucleotide biosynthesis. This gene and PAICS/AIRC, a bifunctional enzyme catalyzing steps six and seven in the purine nucleotide biosynthesis pathway, are located in close proximity on chromosome 4. [provided by RefSeq]
