Parasitism of iron-siderophore receptors of Escherichia coli by the siderophore-peptide microcin E492m - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2005

Parasitism of iron-siderophore receptors of Escherichia coli by the siderophore-peptide microcin E492m

Résumé

Microcins are gene-encoded antibacterial peptides secreted by enterobacteria. They are believed to play a major role in the microbial competitions within the intestinal tract. We have recently isolated a posttranslationally modified form of the 84-residue microcin E492 named MccE492m. MccE492m posttranslational modification was characterized as a trimer of N-(2,3-dihydroxybenzoyl)-L-serine (DHBS) linked to the Ser84-carboxylate via a beta-D-glucose moiety. MccE492m was shown to bind iron through the trimer of DHBS. This is the first example of a novel type of antibacterial peptide called siderophore-peptide. Recognition of both modified and unmodified MccE492 was shown to be mediated by the FepA, Cir and Fiu iron-siderophore receptors at the outer membrane of E. coli. However, the siderophore-mimicking modification was shown to significantly improve the microcin activity. Thus, we propose that MccE492 and MccE492m parasitize iron-siderophore receptors for uptake into the target bacteria and that improvement of MccE492 antimicrobial activity upon modification results from an increase in the microcin/receptor affinity.
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Dates et versions

hal-00013610 , version 1 (09-11-2005)

Identifiants

  • HAL Id : hal-00013610 , version 1

Citer

D. Destoumieux-Garzón, J. Peduzzi, X. Thomas, C. Goulard, A. Blond, et al.. Parasitism of iron-siderophore receptors of Escherichia coli by the siderophore-peptide microcin E492m. 7th International symposium on microbial iron transport storage and metabolism, Jun 2005, Paris, France. ⟨hal-00013610⟩
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