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  • The EMBO Journal (2000) 19, 4473 - 4484
  • doi:10.1093/emboj/19.17.4473

Bacterial SLH domain proteins are non-covalently anchored to the cell surface via a conserved mechanism involving wall polysaccharide pyruvylation

Stéphane Mesnage2, Thierry Fontaine3, Tâm Mignot1, Muriel Delepierre4, Michèle Mock1 and Agnès Fouet1

  1. Toxines et Pathogénie Bactériennes (URA 1858, CNRS), Institut Pasteur, 28 rue du Dr Roux, 75724 Paris, cédex 15, France
  2. Present address: John Innes Centre, Department of Molecular Genetics, Colney Lane, Norwich NR4 7UH, UK
  3. Laboratoire des Aspergillus, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris, cédex 15, France
  4. Laboratoire de Résonance Magnétique Nucléaire (URA 2185 CNRS), Institut Pasteur, 28 rue du Dr Roux, 75724 Paris, cédex 15, France

Correspondence to:

Stéphane Mesnage, E-mail: stephane.mesnage@bbsrc.ac.uk

Received 17 May 2000; Accepted 12 July 2000; Revised 12 July 2000

Several bacterial proteins are non-covalently anchored to the cell surface via an S-layer homology (SLH) domain. Previous studies have suggested that this cell surface display mechanism involves a non-covalent interaction between the SLH domain and peptidoglycan-associated polymers. Here we report the characterization of a two-gene operon, csaAB, for cell surface anchoring, in Bacillus anthracis. Its distal open reading frame (csaB) is required for the retention of SLH-containing proteins on the cell wall. Biochemical analysis of cell wall components showed that CsaB was involved in the addition of a pyruvyl group to a peptidoglycan-associated polysaccharide fraction, and that this modification was necessary for binding of the SLH domain. The csaAB operon is present in several bacterial species that synthesize SLH-containing proteins. This observation and the presence of pyruvate in the cell wall of the corresponding bacteria suggest that the mechanism described in this study is widespread among bacteria.

  • Keywords:

    • Bacillus anthracis,
    • cell wall,
    • pyruvate,
    • SLH motifs,
    • surface targeting