Lectin-like bacteriocins from Pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor

PLoS Pathog. 2014 Feb 6;10(2):e1003898. doi: 10.1371/journal.ppat.1003898. eCollection 2014 Feb.

Abstract

Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of D-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing D-rhamnose and not D-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacteriocins / chemistry
  • Bacteriocins / metabolism*
  • Immunoblotting
  • Lipopolysaccharides / metabolism*
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Polymerase Chain Reaction
  • Protein Structure, Quaternary
  • Pseudomonas aeruginosa / chemistry
  • Pseudomonas aeruginosa / metabolism*
  • Rhamnose / chemistry
  • Rhamnose / metabolism*

Substances

  • Bacteriocins
  • Lipopolysaccharides
  • Rhamnose