Phosphoribosyl-ATP diphosphatase

In enzymology, a phosphoribosyl-ATP diphosphatase is an enzyme that catalyzes the chemical reaction


 * 1-(5-phosphoribosyl)-ATP + H2O $$\rightleftharpoons$$ 1-(5-phosphoribosyl)-AMP + diphosphate

Thus, the two substrates of this enzyme are 1-(5-phosphoribosyl)-ATP and H2O, whereas its two products are 1-(5-phosphoribosyl)-AMP and diphosphate.

This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. The systematic name of this enzyme class is 1-(5-phosphoribosyl)-ATP diphosphohydrolase. Other names in common use include phosphoribosyl-ATP pyrophosphatase, and phosphoribosyladenosine triphosphate pyrophosphatase. This enzyme participates in histidine metabolism. It employs one cofactor, H+.

Structural studies
As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes, , , and.