The DcuS-R two-component system of Escherichia coli senses $C_{4}-dicarboxylates$ of the medium and regulates expression of the genes related to utilization of them. It is known that phospho-DcuR induces expression of genes such as the dcuB-fumB operon, the frdABCD operon, and the dctA gene. We analyzed promoters of the dcuS-R operon to elucidate the transcriptional regulation system. We found a novel internal promoter within the dcuS gene that is regulated by the transcriptional regulator, CRP-cAMP, in both aerobic and anaerobic conditions.