biostudies-literatureUnknown118(4)Saldana-Ahuactzi ZSalmonella enterica spp. produce siderophores to bind iron with high affinity and can also use three xenosiderophores secreted by other microorganisms, ferrichrome, coprogen, and ferrioxamine. Here we focused on FoxA, a TonB-dependent transporter of ferrioxamines. Adjacent to foxA is a gene annotated as a helix-turn-helix (HTH) domain-containing protein, SL0358 (foxR), in the Salmonella enterica serovar Typhimurium SL1344 genome. FoxR shares homology with transcriptional regulators belonging to the AraC/XylS family. foxR is syntenic with foxA in the Enterobacteriaceae family, suggesting their functional relatedness. Both foxA and foxR are repressed by the ferric uptake regulator (Fur) under iron-rich growth conditions. When iron is scarce, FoxR acts as a transcriptional activator of foxA bMolecular microbiology369-386https://www.ebi.ac.uk/biostudies/studies/S-EPMC9804782biostudies-literatureFoxR is an AraC-like transcriptional regulator of ferrioxamine uptake in Salmonella enterica.PMC9804782Knodler LASaldana-Ahuactzi ZfalseFoxR is an AraC-like transcriptional regulator of ferrioxamine uptake in Salmonella enterica.Salmonella enterica spp. produce siderophores to bind iron with high affinity and can also use three xenosiderophores secreted by other microorganisms, ferrichrome, coprogen, and ferrioxamine. Here we focused on FoxA, a TonB-dependent transporter of ferrioxamines. Adjacent to foxA is a gene annotated as a helix-turn-helix (HTH) domain-containing protein, SL0358 (foxR), in the Salmonella enterica serovar Typhimurium SL1344 genome. FoxR shares homology with transcriptional regulators belonging to the AraC/XylS family. foxR is syntenic with foxA in the Enterobacteriaceae family, suggesting their functional relatedness. Both foxA and foxR are repressed by the ferric uptake regulator (Fur) under iron-rich growth conditions. When iron is scarce, FoxR acts as a transcriptional activator of foxA b2022-01-01T00:00:00Z2022 Oct2026-05-28T03:47:05.616Z2025-04-06T00:52:39.207ZS-EPMC98047823597076210.1111/mmi.14970