ID 4.1.1.21 DE phosphoribosylaminoimidazole carboxylase. AN 1-(5-phosphoribosyl)-5-amino-4-imidazolecarboxylate carboxy-lyase. AN 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate carboxy-lyase. AN 5-amino-1-ribosylimidazole 5-phosphate carboxylase. AN 5-phosphoribosyl-5-aminoimidazole carboxylase. AN AIR carboxylase. CA 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate + H(+) = 5-amino- CA 1-(5-phospho-beta-D-ribosyl)imidazole + CO2. CC -!- While this is the reaction that occurs in vertebrates during purine CC biosynthesis, two enzymes are required to carry out the same reaction CC in Escherichia coli, namely EC 6.3.4.18 and EC 5.4.99.18. CC -!- 5-Carboxyamino-1-(5-phospho-D-ribosyl)imidazole is not a substrate. DR Q10457, PUR6_CAEEL ; Q92210, PUR6_CANAL ; O74197, PUR6_CANGA ; DR P38024, PUR6_CHICK ; P0CQ37, PUR6_CRYNB ; P0C017, PUR6_CRYNH ; DR P0CQ36, PUR6_CRYNJ ; Q9I7S8, PUR6_DROME ; P22234, PUR6_HUMAN ; DR Q9DCL9, PUR6_MOUSE ; Q01930, PUR6_OGAME ; Q5RB59, PUR6_PONAB ; DR P51583, PUR6_RAT ; P50504, PUR6_SCHOC ; P15567, PUR6_SCHPO ; DR P55195, PUR6_VIGAC ; P21264, PUR6_YEAST ; Q54QE4, PURCE_DICDI; DR O28997, PURE_ARCFU ; Q73PV9, PURE_TREDE ; //