1-(5-phosphoribosyl)-5-((5-phosphoribosylamino)methylideneamino)imidazole-4-carboxamide isomerase (EC5.3.1.16, N-(5-phospho-D-ribosylformimino)-5-amino-1-(5-phosphoribosyl)-4-imidazolecarboxamide isomerase, phosphoribosylformiminoaminophosphoribosylimidazolecarboxamide isomerase, N-(phosphoribosylformimino) aminophosphoribosylimidazolecarboxamide isomerase, 1-(5-phosphoribosyl)-5-[(5-phosphoribosylamino)methylideneamino]imidazole-4-carboxamide ketol-isomerase) is an enzyme with systematic name1-(5-phosphoribosyl)-5-((5-phosphoribosylamino)methylideneamino)imidazole-4-carboxamide aldose-ketose-isomerase.[1] This enzyme catalyses the following chemical reaction
^Margolies MN, Goldberger RF (July 1966). "Isolation of the fourth (isomerase) of histidine biosynthesis from Salmonella typhimurium". The Journal of Biological Chemistry. 241 (14): 3262–9. PMID5330429.