title: tonB-independent ferrichrome-mediated iron transport in Escherichia coli spheroplasts.
abstract: Although a functional tonB gene product was required for ferrichrome-mediated iron transport in whole cells of Escherichia coli K-12, such transport did not require the tonB+ function in spheroplasts. We suggest that in spheroplasts ferrichrome has direct access to the cytoplasmic membrane and that this is reflected in tonB-independent accumulation of ferrichrome iron. Therefore, the tonB gene product does not function in the translocation of ferrichrome iron across the inner membrane.
mesh_terms: D001693:Biological Transport, Active; D002462:Cell Membrane / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005291:Ferrichrome / Q000378:metabolism*; D005796:Genes; D006877:Hydroxamic Acids / Q000378:metabolism*; D009154:Mutation; D013104:Spheroplasts / Q000378:metabolism*
chemical_list: D006877:Hydroxamic Acids; D005291:Ferrichrome