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Molecular characterization of staphyloferrin B biosynthesis in Staphylococcus aureus
被引:106
作者:
Cheung, Johnson
[1
]
Beasley, Federico C.
[1
]
Liu, Suya
[2
]
Lajoie, Gilles A.
[2
]
Heinrichs, David E.
[1
]
机构:
[1] Univ Western Ontario, Dept Microbiol & Immunol, London, ON N6A 5C1, Canada
[2] Univ Western Ontario, Dept Biochem, London, ON N6A 5C1, Canada
基金:
加拿大自然科学与工程研究理事会;
关键词:
SIDEROPHORE BIOSYNTHESIS;
IRON ACQUISITION;
GENE-CLUSTER;
CITRIC-ACID;
IDENTIFICATION;
PATHWAY;
CONDENSATION;
SYNTHETASES;
SPERMIDINE;
REGULATOR;
D O I:
10.1111/j.1365-2958.2009.06880.x
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
P>Siderophores are iron-scavenging molecules produced by many microbes. In general, they are synthesized using either non-ribosomal peptide synthetase (NRPS) or NRPS-independent siderophore (NIS) pathways. Staphylococcus aureus produces siderophores, of which the structures of staphyloferrin A and staphyloferrin B are known. Recently, the NIS biosynthetic pathway for staphyloferrin A was characterized. Here we show that, in S. aureus, the previously identified sbn (siderophore biosynthesis) locus encodes enzymes required for the synthesis of staphyloferrin B, an alpha-hydroxycarboxylate siderophore comprised of l-2,3-diaminopropionic acid, citric acid, 1,2-diaminoethane and alpha-ketoglutaric acid. Staphyloferrin B NIS biosynthesis was recapitulated in vitro, using purified recombinant Sbn enzymes and the component substrates. In vitro synthesized staphyloferrin B readily promoted the growth of iron-starved S. aureus, via the ABC transporter SirABC. The SbnCEF synthetases and a decarboxylase, SbnH, were necessary and sufficient to produce staphyloferrin B in reactions containing component substrates l-2,3-diaminopropionic acid, citric acid and alpha-ketoglutaric acid. Since 1,2-diaminoethane was not required, this component of the siderophore arises from the SbnH-dependent decarboxylation of a 2,3-diaminoproprionic acid-containing intermediate. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analyses of a series of enzyme reactions identified mass ions corresponding to biosynthetic intermediates, allowing for the first proposed biosynthetic pathway for staphyloferrin B.
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页码:594 / 608
页数:15
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