A direct-sensing galactose chemoreceptor recently evolved in invasive strains of Campylobacter jejuni

Nat Commun. 2016 Oct 20;7:13206. doi: 10.1038/ncomms13206.

Abstract

A rare chemotaxis receptor, Tlp11, has been previously identified in invasive strains of Campylobacter jejuni, the most prevalent cause of bacterial gastroenteritis worldwide. Here we use glycan and small-molecule arrays, as well as surface plasmon resonance, to show that Tlp11 specifically interacts with galactose. Tlp11 is required for the chemotactic response of C. jejuni to galactose, as shown using wild type, allelic inactivation and addition mutants. The inactivated mutant displays reduced virulence in vivo, in a model of chicken colonization. The Tlp11 sensory domain represents the first known sugar-binding dCache_1 domain, which is the most abundant family of extracellular sensors in bacteria. The Tlp11 signalling domain interacts with the chemotaxis scaffolding proteins CheV and CheW, and comparative genomic analysis indicates a likely recent evolutionary origin for Tlp11. We propose to rename Tlp11 as CcrG, Campylobacter ChemoReceptor for Galactose.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Calcium-Binding Proteins / genetics*
  • Calcium-Binding Proteins / metabolism
  • Campylobacter Infections / microbiology
  • Campylobacter jejuni / genetics*
  • Campylobacter jejuni / pathogenicity
  • Chemotaxis / genetics
  • Chickens
  • Galactose / metabolism
  • Humans
  • Monosaccharide Transport Proteins / genetics*
  • Monosaccharide Transport Proteins / metabolism
  • Mutation
  • Periplasmic Binding Proteins / genetics*
  • Periplasmic Binding Proteins / metabolism
  • Protein Binding
  • Sequence Homology, Amino Acid
  • Virulence / genetics

Substances

  • Bacterial Proteins
  • Calcium-Binding Proteins
  • Monosaccharide Transport Proteins
  • Periplasmic Binding Proteins
  • galactose-binding protein
  • Galactose