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From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
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The outer membrane porin OmpW of Acinetobacter baumannii is involved in iron uptake and colistin binding

Manuella Catel-Ferreira1, Sara Marti1,2, Laurent Guillon3

  • 1CNRS UMR 6270 & FR3038, Normandie Univ, Laboratoire Polymères, Biopolymères & Surfaces, Université de Rouen, Mont Saint Aignan, France.

FEBS Letters
|January 30, 2016
PubMed

Insights

The outer membrane protein OmpW in Acinetobacter baumannii facilitates iron uptake but does not contribute to colistin or imipenem resistance. This finding clarifies OmpW

Area of Science:

  • Microbiology
  • Protein Function Analysis
  • Antimicrobial Resistance Research

Background:

  • Acinetobacter baumannii is a significant opportunistic pathogen.
  • Outer membrane proteins play crucial roles in bacterial physiology and antibiotic resistance.
  • OmpW's specific role in A. baumannii, particularly concerning antibiotic resistance, requires detailed characterization.

Purpose of the Study:

  • To investigate the functional properties of the outer membrane protein OmpW in Acinetobacter baumannii.
  • To determine OmpW's potential contribution to colistin and imipenem resistance.
  • To elucidate OmpW's role in iron homeostasis.

Main Methods:

  • Reconstitution of OmpW in artificial lipid bilayers.
  • Electrophysiological measurements to characterize channel activity.
  • Iron uptake assays using (55)Fe in wild-type and ΔompW mutant strains.
  • Susceptibility testing against colistin and imipenem.

Main Results:

  • OmpW forms small ion channels (23 pS in 1 m KCl).
  • OmpW interacts with iron and colistin, but not imipenem.
  • OmpW is confirmed to play a role in iron homeostasis in A. baumannii.
  • Loss of OmpW expression did not affect resistance to colistin or imipenem.

Conclusions:

  • OmpW functions as an iron-related channel in A. baumannii.
  • OmpW is not implicated in the development of colistin or imipenem resistance.
  • OmpW's role is primarily in iron homeostasis, not antibiotic resistance mechanisms.
Keywords:
colistin resistancehydrophobic channeliron homeostasis

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