Phosphoribosyl pyrophosphate

Phosphoribosyl pyrophosphate (PRPP) is a pentosephosphate.

It is formed from ribose 5-phosphate by the enzyme ribose-phosphate diphosphokinase.

It plays a role in transferring phospho-ribose groups in several reactions:

In de novo generation of purines, the enzyme amidophosphoribosyltransferase acts upon PRPP to create phosphoribosylamine.