Genetic and molecular characterization of essential components of the Vibrio anguillarum plasmid-mediated iron-transport system.
The iron-transport genes from the pJM1 plasmid of Vibrio anguillarum have been cloned and sequenced. Five open-reading frames have been identified, one of which encodes the outer membrane receptor for ferric anguibactin, OM2. This coding region corresponds to a protein of 726 amino acids with a Mr of 78,777. The protein has a hydrophobic signal sequence of 35 amino acids and a potential membrane-associated hydrophobic region at the carboxyl terminus. A 2.3-kilobase iron-regulated mRNA was transcribed from this region in vivo. The four other open-reading frames were shown to be involved in the regulation of OM2 expression and in iron transport by the use of insertion mutagenesis and complementation analysis. One of these open-reading frames, ORF3, encodes a 40-kDa polypeptide which, as deduced from the amino acid sequence and the hydropathy plot, is likely to be membrane-associated and together with OM2 may play a role in the transport of iron into the cell cytosol.
Actis
L A
LA
Department of Microbiology and Immunology, School of Medicine, Oregon Health Sciences University, Portland 97201.
Tolmasky
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ME
Farrell
D H
DH
Crosa
J H
JH
D000595:Amino Acid Sequence; D001345:Autoradiography; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics*; D001483:Base Sequence; D001693:Biological Transport, Active; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D007163:Immunosorbent Techniques; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents; D010455:Peptides; D010957:Plasmids; D017262:Siderophores; D014733:Vibrio / Q000235:genetics*
D001426:Bacterial Proteins; D007502:Iron Chelating Agents; D010455:Peptides; D017262:Siderophores; C049469:anguibactin; D007501:Iron; D004262:DNA Restriction Enzymes