GTP cyclohydrolase II

Template:Infobox enzyme In enzymology, a GTP cyclohydrolase II (Template:EC number) is an enzyme that catalyzes the chemical reaction

GTP + 3 H₂O $\rightleftharpoons$ formate + 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + diphosphate

Thus, the two substrates of this enzyme are GTP and H₂O, whereas its 3 products are formate, 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine, and diphosphate.

This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is GTP 7,8-8,9-dihydrolase (diphosphate-forming). Other names in common use include guanosine triphosphate cyclohydrolase II, and GTP-8-formylhydrolase. This enzyme participates in riboflavin metabolism.

Structural studies

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

References

• Template:Cite journal

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