title: Characterization and regulation of the expression of FatB, an iron transport protein encoded by the pJM1 virulence plasmid.
abstract: The pJM1-encoded genes fatDCBA are essential for iron acquisition via the siderophore anguibactin. Sequence analysis indicated that the open reading frame corresponding to the fatB gene possesses domains that are characteristic of periplasmic proteins that bind the ferric siderophore. In this work, a monospecific antiserum against an oligopeptide containing the last 27 amino acids of the carboxy-terminal region from this open reading frame was used to demonstrate that fatB encodes a 35 kDa protein that is essential for iron transport. By using this antibody we were able to demonstrate that expression of the fatB gene is negatively regulated by the Fur protein at high iron concentrations. Conversely, its expression was positively regulated by the combined action of the AngR protein and products of the TAF region. FatB, the product of the fatB gene, is isolated with the membrane fraction. In accordance with these findings is the fact that the first 23 amino acid residues of this protein have the properties of a lipoprotein signal sequence. The lipoprotein nature of FatB is supported by the fact that treatment of Vibrio anguillarum cells with globomycin, an inhibitor of the lipoprotein signal peptidase, results in the accumulation of a 38 kDa proFatB precursor protein.
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D002352:Carrier Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry; D004268:DNA-Binding Proteins; D010450:Endopeptidases; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005798:Genes, Bacterial / Q000235:genetics; D033862:Iron-Binding Proteins; D008074:Lipoproteins / Q000032:analysis; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D010455:Peptides; D010957:Plasmids / Q000235:genetics*; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000502:physiology; D012697:Serine Endopeptidases; D014157:Transcription Factors / Q000502:physiology; D033863:Transferrin-Binding Proteins; D014733:Vibrio / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C071991:FatB protein, Vibrio anguillarum; D033862:Iron-Binding Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010455:Peptides; D011480:Protease Inhibitors; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D033863:Transferrin-Binding Proteins; C063474:angR protein, Vibrio anguillarum; C068477:ferric uptake regulating proteins, bacterial; C017339:globomycin; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase