Ribose-Phosphate Pyrophosphokinase 2 (PRPS2) is a phosphoribosyl pyrophosphate synthetase that belongs to the ribose-phosphate pyrophosphokinase family. PRPS2 is a homodimer. The active form is probably an hexamer composed of three homodimers. PRPS2 catalyzes the synthesis of phosphoribosylpyrophosphate (PRPP) that is essential for nucleotide synthesis. PRPS2 catalyzes the synthesis of 5-phosphoribosyl 1-pyrophosphate from ATP and D-ribose 5-phosphate. In addition, PRPS2 plays a central role in the synthesis of purines and pyrimidines.