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Plant lectin-like bacteriocin from a rhizosphere-colonizing Pseudomonas isolate
Annabel H A Parret1, Geert Schoofs, Paul Proost
1Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium. annabel.parret@agr.kuleuven.ac.be
Journal of Bacteriology
|January 21, 2003
Summary
Researchers discovered a novel bacteriocin, LlpA, produced by Pseudomonas sp. strain BW11M1. This lectin-like protein, enhanced by DNA damage, inhibits other Pseudomonas strains and represents a new class of bacterial defense mechanism.
Area of Science:
- Microbiology
- Bacteriology
- Molecular Biology
Background:
- Pseudomonas sp. strain BW11M1 produces a bacteriocin targeting P. putida GR12-2R3.
- Bacteriocin production is inducible by DNA-damaging agents.
- The bacteriocin is heat- and protease-sensitive.
Purpose of the Study:
- To identify and characterize the bacteriocin produced by Pseudomonas sp. strain BW11M1.
- To elucidate the genetic basis of bacteriocin production.
- To understand the evolutionary and functional significance of the bacteriocin.
Main Methods:
- Isolation and characterization of a TnMod mutant.
- Cloning and heterologous expression of the bacteriocin gene in Escherichia coli.
- Bioinformatic analysis including sequence homology and phylogenetic analysis.
- Determination of protein domains and secretion mechanism.
Main Results:
- A mutant deficient in bacteriocin production was identified.
- The bacteriocin structural gene, llpA, was identified and characterized.
- LlpA shares homology with monocot mannose-binding lectin (MMBL) domains.
- Phylogenetic analysis revealed a new bacterial clade of MMBL-containing proteins.
- LlpA secretion occurs without a cleavable signal sequence.
- Heterologous expression confirmed llpA's role in bacteriocin production.
Conclusions:
- Pseudomonas sp. strain BW11M1 produces a novel lectin-like bacteriocin, LlpA.
- LlpA represents a new class of bacteriocins with potential unique mechanisms of action.
- The discovery expands our understanding of bacterial defense mechanisms and protein evolution.