Identification and molecular characterization of a novel Salmonella enteritidis pathogenicity islet encoding an ABC transporter.
Using a newly constructed minitransposon with a phoA reporter gene in a Salmonella enteritidis phoN mutant, we have identified an iron- and pH-inducible lipoprotein gene sfbA, which is a component of a novel ABC-type transporter system required for virulence. This gene is located on a 4 kb Salmonella-specific chromosomal segment, which constitutes a new pathogenicity islet. This islet encodes an outer membrane protein, OmpX, and contains the operon designated sfbABC (Salmonella ferric binding) encoding a putative periplasmic iron-binding lipoprotein SfbA, a nucleotide-binding ATPase SfbB and a cytoplasmic permease SfbC, as predicted by their characteristic signature sequences. Inactivation of the sfbA gene resulted in a mutant that is avirulent and induces protective immunity in BALB/c mice. The wild-type phenotype could be restored by in vivo complementation with the sfbABC operon. This novel transporter might be involved in iron uptake in Salmonella.
Pattery
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Laboratorium voor Genetische Virologie, Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint-Genesius-Rode, Belgium.
Hernalsteens
J P
JP
De Greve
H
H
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D017930:Genes, Reporter; D006867:Hydrolases; D033862:Iron-Binding Proteins; D008074:Lipoproteins / Q000737:chemistry / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009154:Mutation; D033902:Periplasmic Binding Proteins; D012333:RNA, Messenger / Q000378:metabolism; D012477:Salmonella enteritidis / Q000235:genetics* / Q000472:pathogenicity; D016415:Sequence Alignment; D012703:Serotyping; D033863:Transferrin-Binding Proteins; D014774:Virulence / Q000235:genetics
D018528:ATP-Binding Cassette Transporters; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D033862:Iron-Binding Proteins; D008074:Lipoproteins; D033902:Periplasmic Binding Proteins; D012333:RNA, Messenger; C438830:SfbA protein, Salmonella; D033863:Transferrin-Binding Proteins; C482905:OmpX protein, E coli; D006867:Hydrolases