4.1.1.21 phosphoribosylaminoimidazole carboxylase; 5-phosphoribosyl-5-aminoimidazole carboxylase; 5-amino-1-ribosylimidazole 5-phosphate carboxylase; AIR carboxylase; 1-(5-phosphoribosyl)-5-amino-4-imidazolecarboxylate carboxy-lyase; ADE2; class II PurE; 5-a • • •