The virulence-associated chrysobactin iron uptake system of Erwinia chrysanthemi 3937 involves an operon encoding transport and biosynthetic functions.
The iron assimilation system of Erwinia chrysanthemi 3937 is mediated by the catechol-type siderophore chrysobactin and the outer membrane transport protein Fct. We generated a variety of subclones in high- and low-copy-number vectors from a wild-type recombinant cosmid shown previously to carry the gene cluster fct-cbsA, cbsB, cbsC, cbsE encoding chrysobactin transport and biosynthetic functions, respectively. We studied their expression in Escherichia coli enterobactin-deficient entA, entB, entC, and entE mutants. This provided evidence that the fct and cbs genes are regrouped within a single genetic unit of ca. 8 kb in the following order: fct, cbsC, cbsE, cbsB, and cbsA. The gene boundaries were determined, and the various recombinant plasmids were expressed in Escherichia coli minicells: CbsA and CbsC enzymatic activities were clearly identified as polypeptides with apparent molecular masses of 32,000 and 38,000, respectively.
Franza
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Laboratoire de Pathologie Végétale, Institut National de la Recherche Agronomique, Paris, France.
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D001692:Biological Transport; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D016974:Dickeya chrysanthemi / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D004151:Dipeptides / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D007501:Iron / Q000378:metabolism*; D005810:Multigene Family; D009876:Operon; D011956:Receptors, Cell Surface / Q000235:genetics; D015183:Restriction Mapping; D014774:Virulence / Q000235:genetics
D004151:Dipeptides; D011956:Receptors, Cell Surface; C058543:chrysobactin; D007501:Iron