Molecular function

10-formyltetrahydrofolate:5'-phosphoribosyl-5-amino-4-imidazole-carboxamide N-formyltransferase activity, 10-formyltetrahydrofolate:5'-phosphoribosyl-5-amino-4-imidazolecarboxamide formyltransferase activity, 5'-phosphoribosyl-5-amino-4-imidazolecarboxamide formyltransferase activity, 5-amino-1-ribosyl-4-imidazolecarboxamide 5'-phosphate transformylase activity, 5-amino-4-imidazolecarboxamide ribonucleotide transformylase activity, 5-amino-4-imidazolecarboxamide ribotide transformylase activity, AICAR formyltransferase activity, AICAR transformylase activity, aminoimidazolecarboxamide ribonucleotide transformylase activity

Catalysis of the reaction: 10-formyltetrahydrofolate + 5'-phosphoribosyl-5-amino-4-imidazolecarboxamide = tetrahydrofolate + 5'-phosphoribosyl-5-formamido-4-imidazolecarboxamide.