C-terminal WxL domain mediates cell wall binding in Enterococcus faecalis and other gram-positive bacteria.
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.
Brinster
Sophie
S
Unité des Bactéries Lactiques et Pathogènes Opportunistes, INRA, Jouy-en-Josas, France.
Furlan
Sylviane
S
Serror
Pascale
P
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D001482:Base Composition; D002473:Cell Wall / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016680:Genome, Bacterial; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism; D008087:Listeria / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism; D013292:Streptococcus agalactiae / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D008565:Membrane Proteins