FurA modulates gene expression of alr3808, a DpsA homologue in Nostoc (Anabaena) sp. PCC7120

The DNA-binding protein from stationary phase (Dps) protein family plays an important role in protecting microorganisms from oxidative and nutritional stresses. In silico analysis of the promoter region of alr3808, a dpsA homologue from the cyanobacterium Nostoc sp. PCC7120 shows putative iron-boxes with high homology with those recognized by FurA (ferric uptake regulator). Evidence for the modulation of dpsA by FurA was obtained using in vitro and in vivo approaches. SELEX linked to PCR was used to identify P_dpsA as a FurA target. Concurrently, EMSA assays showed high affinity of FurA for the dpsA promoter region. DpsA expression analysis in an insertional mutant of the alr1690-αfurA message (that exhibited an increased expression of FurA) showed a reduced synthesis of DpsA. These studies suggest that FurA plays a significant role in the regulation of the DpsA.