C-terminal WxL domain mediates cell wall binding in Enterococcus faecalis and other gram-positive bacteria

J Bacteriol. 2007 Feb;189(4):1244-53. doi: 10.1128/JB.00773-06. Epub 2006 Sep 8.

Abstract

Analysis of the genome sequence of Enterococcus faecalis clinical isolate V583 revealed novel genes encoding surface proteins. Twenty-seven of these proteins, annotated as having unknown functions, possess a putative N-terminal signal peptide and a conserved C-terminal region characterized by a novel conserved domain designated WxL. Proteins having similar characteristics were also detected in other low-G+C-content gram-positive bacteria. We hypothesized that the WxL region might be a determinant of bacterial cell location. This hypothesis was tested by generating protein fusions between the C-terminal regions of two WxL proteins in E. faecalis and a nuclease reporter protein. We demonstrated that the C-terminal regions of both proteins conferred a cell surface localization to the reporter fusions in E. faecalis. This localization was eliminated by introducing specific deletions into the domains. Interestingly, exogenously added protein fusions displayed binding to whole cells of various gram-positive bacteria. We also showed that the peptidoglycan was a binding ligand for WxL domain attachment to the cell surface and that neither proteins nor carbohydrates were necessary for binding. Based on our findings, we propose that the WxL region is a novel cell wall binding domain in E. faecalis and other gram-positive bacteria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / metabolism*
  • Base Composition
  • Cell Wall / metabolism*
  • Enterococcus faecalis / genetics*
  • Enterococcus faecalis / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Genome, Bacterial
  • Lactobacillus / genetics
  • Lactobacillus / metabolism
  • Listeria / genetics
  • Listeria / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Molecular Sequence Data
  • Protein Binding
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / metabolism
  • Streptococcus agalactiae / genetics
  • Streptococcus agalactiae / metabolism

Substances

  • Bacterial Proteins
  • Membrane Proteins

Associated data

  • GENBANK/AE016830