The enzyme phosphoribosyl pyrophosphate synthetase (PRPP synthetase) catalyzes the conversion of ribose-5-phosphate into its 1-pyrophosphate derivative, as
Question:
The enzyme phosphoribosyl pyrophosphate synthetase (PRPP synthetase) catalyzes the conversion of ribose-5-phosphate into its 1-pyrophosphate derivative, as shown in Fig. P25.39. The pyrophosphate group in the product is provided by ATP, not shown in the figure.
(a) At which phosphate of ATP does the nucleophilic hydroxy group of ribose-5-phosphate react? What is the by-product of the reaction?
PRPP is an important intermediate in the biosynthesis of nucleic acids and amino acids. It reacts with nucleophiles at carbon-1 in typical SN2-like processes.
(b) To illustrate this reactivity, show the reaction of ammonia with PRPP. Be sure to show the stereochemistry.
(c) A by-product of the reaction in part (b) is pyrophosphate.
What other biochemical reaction ensures that the reaction you drew in part (b) runs to completion?
Step by Step Answer:
a b The nucleophilic hydroxyl group reacts at the Bphosphate group a...View the full answer
