Catalysis of the reaction: GTP + 2 H2O = formate + 2-amino-4-hydroxy-6-(erythro-1,2,3-trihydroxypropyl)-dihydropteridine triphosphate [goid 3934] [pmid 3753653] [evidence IDA]; Catalysis of the reaction: GTP + 2 H2O = formate + 2-amino-4-hydroxy-6-(erythro-1,2,3-trihydroxypropyl)-dihydropteridine triphosphate [goid 3934] [pmid 11284739] [evidence IDA]; Catalysis of the reaction: GTP + 2 H2O = formate + 2-amino-4-hydroxy-6-(erythro-1,2,3-trihydroxypropyl)-dihydropteridine triphosphate [goid 3934] [pmid 8068008] [evidence IDA]; Catalysis of the reaction: GTP + 2 H2O = formate + 2-amino-4-hydroxy-6-(erythro-1,2,3-trihydroxypropyl)-dihydropteridine triphosphate [goid 3934] [pmid 16778797] [evidence IDA]; Catalysis of the reaction: GTP + 2 H2O = formate + 2-amino-4-hydroxy-6-(erythro-1,2,3-trihydroxypropyl)-dihydropteridine triphosphate [goid 3934] [pmid 8068008] [evidence IDA]; Interacting selectively with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules) [goid 5515] [pmid 9092499] [evidence IPI]; Interacting selectively with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules) [goid 5515] [pmid 16696853] [evidence IPI]; Interacting selectively with GTP, guanosine triphosphate [goid 5525] [pmid 3753653] [evidence IDA]; Interacting selectively with GTP, guanosine triphosphate [goid 5525] [pmid 14717702] [evidence IDA]; Interacting selectively with zinc (Zn) ions [goid 8270] [pmid 11087823] [evidence IDA]; Interacting selectively with zinc (Zn) ions [goid 8270] [pmid 14717702] [evidence IDA]; Catalysis of the hydrolysis of various bonds, e.g. C-O, C-N, C-C, phosphoric anhydride bonds, etc. Hydrolase is the systematic name for any enzyme of EC class 3 [goid 16787] [evidence IEA]; Interacting selectively with an identical protein to form a homodimer [goid 42803] [pmid 1669853] [evidence IPI]; Interacting selectively with any metal ion [goid 46872] [evidence IEA]