Guanosine-5'-triphosphate,3'-diphosphate diphosphatase

In enzymology, a guanosine-5'-triphosphate,3'-diphosphate diphosphatase is an enzyme that catalyzes the chemical reaction


 * guanosine 5'-triphosphate,3'-diphosphate + H2O $$\rightleftharpoons$$ guanosine 5'-diphosphate,3'-diphosphate + phosphate

Thus, the two substrates of this enzyme are guanosine 5'-triphosphate,3'-diphosphate and H2O, whereas its two products are guanosine 5'-diphosphate,3'-diphosphate and phosphate.

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 guanosine-5'-triphosphate,3'-diphosphate 5'-phosphohydrolase. Other names in common use include pppGpp 5'-phosphohydrolase, guanosine-5'-triphosphate,3'-diphosphate pyrophosphatase, guanosine 5'-triphosphate-3'-diphosphate 5'-phosphohydrolase, guanosine pentaphosphatase, guanosine pentaphosphate phosphatase, guanosine 5'-triphosphate 3'-diphosphate 5'-phosphatase, and guanosine pentaphosphate phosphohydrolase. This enzyme participates in purine metabolism.

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