The outer membrane porin OmpW of Acinetobacter baumannii is involved in iron uptake and colistin binding

FEBS Lett. 2016 Jan;590(2):224-31. doi: 10.1002/1873-3468.12050. Epub 2016 Jan 11.

Abstract

This study was undertaken to characterize functions of the outer membrane protein OmpW, which potentially contributes to the development of colistin- and imipenem-resistance in Acinetobacter baumannii. Reconstitution of OmpW in artificial lipid bilayers showed that it forms small channels (23 pS in 1 m KCl) and markedly interacts with iron and colistin, but not with imipenem. In vivo, (55) Fe uptake assays comparing the behaviours of ΔompW mutant and wild-type strains confirmed a role for OmpW in A. baumannii iron homeostasis. However, the loss of OmpW expression did not have an impact on A. baumannii susceptibilities to colistin or imipenem.

Keywords: colistin resistance; hydrophobic channel; iron homeostasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / metabolism*
  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / isolation & purification
  • Bacterial Outer Membrane Proteins / metabolism*
  • Colistin / metabolism*
  • Iron / metabolism*
  • Molecular Sequence Data
  • Porins / chemistry
  • Porins / isolation & purification
  • Porins / metabolism*
  • Protein Binding
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid

Substances

  • Bacterial Outer Membrane Proteins
  • Porins
  • Recombinant Proteins
  • Iron
  • Colistin