Description | A nine-gene operon, sbn, encodes genes for staphylobactin biosynthesis and export. This siderophore, or ferric iron (Fe3+) chelator, contributes to survival, and therefore virulence, by Staphylococcus aureus in host tissues. Its reported size by m/z is 822, larger than staphyloferrins A (480) or B (448). SbnD appears to be the efflux transporter, SbnI is not homologous to known enzymes, and the other seven all appear by homology to be enzymes. Mutation of SbnE leads to a defect in staphylobactin biosynthesis, and an adjacent ABC transporter system, not currently part of this genome property, takes up ferric staphylobactin. Note that staphylobactin may be closely to staphyloferrin B, as all proteins but sbnI have close homologs in Ralstonia solanacearum GMI1000, which is phylogenetically extremely distant. R. solanacearum, however, makes staphyloferrin B like most strains of Staphylococcus aureus. S. aureus RN6390, meanwhile, appears to makes staphylobactin in place of staphyloferrin B. |
Literature References | [ 1 ] Dale SE, Doherty-Kirby A, Lajoie G, Heinrichs DE Role of siderophore biosynthesis in virulence of Staphylococcus aureus: identification and characterization of genes involved in production of a siderophore. Infect Immun. 2004 Jan;72(1):29-37. PMID 14688077 [ 2 ] Dale SE, Sebulsky MT, Heinrichs DE Involvement of SirABC in iron-siderophore import in Staphylococcus aureus. J Bacteriol. 2004 Dec;186(24):8356-62. PMID 15576785 [ 3 ] Bhatt G, Denny TP Ralstonia solanacearum iron scavenging by the siderophore staphyloferrin B is controlled by PhcA, the global virulence regulator. J Bacteriol. 2004 Dec;186(23):7896-904. PMID 15547261 |
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