The Importance of PRPP

5-Phospho--D-ribosyl-1-pyrophosphate (PRPP) is an intermediate in both the de novo synthesis of nucleotides (Figure 22.1) and the salvage synthesis (reutilization) of nucleotides (Figure 22.2).

PRPP is synthesized from ribose-5-phosphate as shown here.

PRPP is converted to a nucleotide by addition of a base, as shown here. This reaction is reversible, but it proceeds almost exclusively to the right in cells, due to the PPi product, which is readily cleaved by phosphodiesterases.

See also: De Novo Biosynthesis of Purine Nucleotides, PRPP Amidotransferase, Figure 22.4

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> 1. Purine Metabolism

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