Characterization of Ferric and Ferrous Iron Transport Systems in Vibrio cholerae

摘要: Vibrio cholerae has multiple iron acquisition systems, including TonB-dependent transport of heme and the catechol siderophore vibriobactin. Strains defective in both these systems grow well laboratory media infant mouse intestine, indicating presence additional systems. Previously uncharacterized potential a homologue ferrous transporter Feo periplasmic binding protein-dependent ATP cassette (ABC) system, termed Fbp, were identified V. genome sequence. Clones encoding either or Fbp system exhibited characteristics transporters: repressed expression lacZ cloned under control Fur-regulated promoter Escherichia coli also conferred growth on Shigella flexneri mutant that severe defect transport. Two other ABC transporters evaluated but negative by assays. Transport radioactive into S. was stimulated reducing agent ascorbate, consistent with functioning as transporter. Conversely, ascorbate inhibited suggesting it transports ferric iron. The strains carrying mutations one more genes indicated contribute to acquisition. However, vibriobactin, not attenuated suckling model, at least can be used vivo.