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

Stéphane Mesnage (1) , Thierry Fontaine (2) , Tâm Mignot (3) , Muriel Delepierre (4) , Michèle Mock (3) , Agnès Fouet (3)

1 John Innes Centre [Norwich]
2 Aspergillus
3 Toxines et Pathogénie Bactérienne
4 Résonance Magnétique Nucléaire des Biomolécules

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.

Domains: Life Sciences [q-bio]; Biochemistry, Molecular Biology; Structural Biology [q-bio.BM]

Stéphane Mesnage, Thierry Fontaine, Tâm Mignot, Muriel Delepierre, Michèle Mock, et al.. Bacterial SLH domain proteins are non-covalently anchored to the cell surface via a conserved mechanism involving wall polysaccharide pyruvylation.. EMBO Journal, 2000, 19 (17), pp.4473-84. ⟨10.1093/emboj/19.17.4473⟩. ⟨pasteur-00370366⟩