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From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
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From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins

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Structure of the outer membrane porin OmpW from the pervasive pathogen Klebsiella pneumoniae

Chloe Seddon1, Gad Frankel1, Konstantinos Beis1

  • 1Department of Life Sciences, Imperial College, London, United Kingdom.

Acta Crystallographica. Section F, Structural Biology Communications
|January 11, 2024
PubMed

Insights

Bacterial conjugation, a method for transferring antibiotic resistance genes, depends on outer membrane protein interactions. This study reveals the crystal structure of Klebsiella pneumoniae OmpW, crucial for plasmid R100-1 conjugation.

Area of Science:

  • Microbiology
  • Structural Biology
  • Genetics

Background:

  • Bacterial conjugation facilitates the transfer of genetic material, including antibiotic resistance genes, between bacteria.
  • Efficient conjugation of IncF-like plasmids requires stable mating pairs formed by interactions between donor and recipient outer membrane proteins.
  • The R100-1 plasmid utilizes the interaction between donor TraNα and recipient OmpW for conjugation into Escherichia coli and Klebsiella pneumoniae.

Purpose of the Study:

  • To determine the crystal structure of OmpW from Klebsiella pneumoniae (OmpWKP).
  • To provide structural insights into the OmpW protein involved in bacterial conjugation.

Main Methods:

  • X-ray crystallography was used to determine the 3.2 Å resolution structure of OmpWKP.
  • Comparative structural analysis of OmpWKP and OmpWEC (from E. coli).

Main Results:

  • The crystal structure of OmpWKP revealed an eight-stranded β-barrel structure with flanking extracellular loops.
  • High structural conservation was observed between OmpWEC and OmpWKP, particularly in the β-barrel core, despite sequence variations in extracellular loops.

Conclusions:

  • The determined structure of OmpWKP provides a molecular basis for understanding its role in bacterial conjugation.
  • Structural conservation suggests a conserved function of OmpW in different bacterial species during plasmid transfer.
Keywords:
Klebsiella pneumoniaeOmpWbacterial conjugationouter membrane porinβ-barrel

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