Term Name:	GTP cyclohydrolase II activity
Synonyms:	GTP 7,8-8,9-dihydrolase (diphosphate-forming), GTP-8-formylhydrolase activity, guanosine triphosphate cyclohydrolase II
Definition:	Catalysis of the reaction: GTP + 4 H2O = 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)-pyrimidine + formate + 3 H+ + 2 phosphate.
Ontology:	GO: Molecular Function [GO:0003935]    QuickGO    AmiGO