TonB-independent ferrioxamine B-mediated iron transport in Escherichia coli K12.
The TonB protein of Escherichia coli K12 couples the energized state of the cytoplasmic membrane with energy-dependent receptors in the outer membrane. High affinity iron transport mediated by ferric dicitrate, ferrienterobactin, ferriaerobactin, ferrichrome, and coprogen all require a functional tonB protein. However, we have found no difference between the growth rates of tonB+ strains and tonB strains using ferrioxamine B as the sole iron source. This TonB-independence of FOB transport and earlier results with a photoactive FOB analog indicate a separate mechanism for iron acquisition from FOB in E. coli.
Nelson
M
M
Department of Microbiology, University of Texas, Austin 78712.
Szaniszlo
P J
PJ
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001693:Biological Transport, Active; D003676:Deferoxamine / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005290:Ferric Compounds / Q000378:metabolism*; D005798:Genes, Bacterial; D007501:Iron / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D005290:Ferric Compounds; D008565:Membrane Proteins; C057616:tonB protein, Bacteria; C489181:tonB protein, E coli; C002577:ferrioxamine B; D007501:Iron; D003676:Deferoxamine