GTP cyclohydrolase II
{{infobox enzyme
| Name = GTP cyclohydrolase II
| EC_number = 3.5.4.25
| CAS_number = 56214-35-8
| GO_code = 0003935
| image =
| width =
| caption =
}}
In enzymology, a GTP cyclohydrolase II ({{EC number|3.5.4.25}}) is an enzyme that catalyzes the chemical reaction
:GTP + 3 H2O 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 {{PDB link|2BZ0}} and {{PDB link|2BZ1}}.
References
{{reflist|1}}
- {{cite journal | vauthors = Foor F, Brown GM | date = 1975 | title = Purification and properties of guanosine triphosphate cyclohydrolase II from Escherichia coli | journal = J. Biol. Chem. | volume = 250 | pages = 3545–51 | pmid = 235552 | issue = 9 | doi = 10.1016/S0021-9258(19)41549-4 | doi-access = free }}
{{Carbon-nitrogen non-peptide hydrolases}}
{{Enzymes}}
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Category:Enzymes of known structure
{{3.5-enzyme-stub}}