Biometals

, Volume 19, Issue 2, pp 181–191

Parasitism of Iron-siderophore Receptors of Escherichia Coli by the Siderophore-peptide Microcin E492m and its Unmodified Counterpart

  • Delphine Destoumieux-Garzón
  • Jean Peduzzi
  • Xavier Thomas
  • Chakib Djediat
  • Sylvie Rebuffat
Article

DOI: 10.1007/s10534-005-4452-9

Cite this article as:
Destoumieux-Garzón, D., Peduzzi, J., Thomas, X. et al. Biometals (2006) 19: 181. doi:10.1007/s10534-005-4452-9

Abstract

Microcin E492 (MccE492) is an antibacterial peptide naturally secreted by Klebsiella pneumoniae RYC492. Initially described as an 84-residue unmodified peptide, it was also recently isolated in a posttranslationally modified form, MccE492m. The production of MccE492m is dependent on the synthesis of enterobactin and the mceABCDEFGHIJ gene cluster. The posttranslational modification was characterized as a trimer of N-(2,3-dihydroxybenzoyl)-l-serine (DHBS) linked to the Ser84-carboxylate via a β-d-glucose moiety. MccE492m was shown to bind ferric ions through the trimer of DHBS. This is the first example of a novel type of antibacterial peptide termed siderophore-peptide. Recognition of MccE492m, but also of the unmodified MccE492, was shown to be mediated by the catecholate siderophore receptors FepA, Cir and Fiu at the outer membrane of E. coli. The siderophore-type modification was shown to be responsible for a significant enhancement of the microcin antibacterial activity. Therefore, we propose that MccE492 and MccE492m use 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.

Key words

catecholate siderophore Escherichia coli iron-siderophore receptors microcin E492 siderophore-peptide 

Copyright information

© Springer 2006

Authors and Affiliations

  • Delphine Destoumieux-Garzón
    • 1
  • Jean Peduzzi
    • 1
  • Xavier Thomas
    • 1
  • Chakib Djediat
    • 2
  • Sylvie Rebuffat
    • 1
  1. 1.Chemistry, Biochemistry of Natural Substances, Department Regulations, Development and Molecular DiversityUMR 5154 CNRS – National Museum of Natural HistoryParisFrance
  2. 2.Electronic Microscopy FacilitiesNational Museum of Natural HistoryParisFrance

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