The three structural genes (araB, araA, araD) encode for enzymes needed for the metabolism of the sugar arabinose in bacterial cells. AraB, araA, and araD encode for the enzymes kinase, isomerase, and epimerase. Isomerase converts arabinose to ribulose. Kinase converts ribulose to ribulose-5-phosphate. Then, epimerase converts ribulose-5-phosphate to xyulose-5-phosphate, which enters the glycolytic pathway for carbon metabolism.