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Updated: Feb 13, 2026
20:23
A Lectin HPLC Method to Enrich Selectively-glycosylated Peptides from Complex Biological Samples
Published on: October 1, 2009
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Hitting with a BAM: Selective Killing by Lectin-Like Bacteriocins.
Maarten G K Ghequire1, Toon Swings2,3, Jan Michiels2,3
1Centre of Microbial and Plant Genetics, KU Leuven, Heverlee, Belgium maarten.ghequire@biw.kuleuven.be.
Mbio
|March 22, 2018
Summary
Lectin-like bacteriocins (LlpAs) use the outer membrane protein BamA as a receptor, not for uptake. Mutations in BamA
Area of Science:
- Microbiology
- Bacteriology
- Molecular Biology
Background:
- Bacteriocins are antimicrobial peptides used by bacteria to eliminate rivals.
- Lectin-like bacteriocins (LlpAs) are secreted by proteobacteria and possess two B-lectin domains.
- LlpAs selectively kill strains of their own or related species, with distinct domains for binding and killing.
Purpose of the Study:
- To identify the cellular receptor and mechanism of action for LlpAs in *Pseudomonas* spp.
- To investigate the role of the BamA protein in LlpA susceptibility and selectivity.
- To elucidate a novel bacteriocin killing mechanism independent of cellular uptake.
Main Methods:
- Isolation and characterization of LlpA-resistant mutants in *Pseudomonas*.
- Genetic analysis of mutations in resistant strains, focusing on the BamA protein.
- Heterologous expression of *bamA* genes to assess LlpA susceptibility.
Main Results:
- Spontaneous LlpA-resistant mutants harbor mutations in the essential outer membrane protein insertase, BamA.
- Specific surface-exposed loops of BamA determine LlpA susceptibility, with a conserved signature motif in targeted strains.
- Heterologous expression of susceptible *bamA* genes confers LlpA sensitivity to resistant strains.
Conclusions:
- BamA acts as the primary receptor and selectivity determinant for LlpAs in pseudomonads.
- LlpAs employ a novel killing mechanism by impairing BamA function, rather than requiring cellular uptake.
- This mechanism represents a new form of bacterial antagonism, parasitizing an essential cellular machine.
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