Phosphoribosyl Pyrophosphate (PRPP)

PRPP is an intermediate in nucleotide metabolism. It is found in several de novo and salvage pathways. PRPP is formed by action of the enzyme, PRPP Synthetase, as follows:

ATP + Ribose-5-Phosphate <=> PRPP + AMP

Enzymes that act on PRPP include Phosphoribosyltransferases (salvage synthesis and de novo synthesis of pyrimidines), PRPP amidotransferase (de novo purine synthesis)

See also: De Novo Biosynthesis of Purine Nucleotides, De Novo Pyrimidine Nucleotide Metabolism, Nucleotide Salvage Synthesis