Tags: Enzyme.
Phosphoribosylaminoimidazole carboxylase (or AIR carboxylase) is an enzyme involved in nucleotide biosynthesis and in particular in purine biosynthesis. It catalyzes the conversion of 5′-phosphoribosyl-5-aminoimidazole (AIR) into 5′-phosphoribosyl-4-carboxy-5-aminoimidazole (CAIR) as described in the reaction:5-aminoimidazole ribonucleotide + CO2 5′-phosphoribosyl-4-carboxy-5-aminoimidazole + 2 H+