has participant water IMP(2-) 5-formamido-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide(2-) IMP cyclohydrolase activity IMP synthetase activity molecular_function inosinicase activity inosinate cyclohydrolase activity Catalysis of the reaction: IMP + H2O = 5-formamido-1-(5-phosphoribosyl)imidazole-4-carboxamide. MetaCyc:IMPCYCLOHYDROLASE-RXN Reactome:R-HSA-73797 IMP 1,2-hydrolase (decyclizing) GO:0003937 RHEA:18445 EC:3.5.4.10 cyclohydrolase activity