Journal Article

Lactobacillus surface layer proteins: structure, function and applications

Palva, Airi, Hynönen, Ulla

2013

Overview

Bacterial surface (S) layers are the outermost proteinaceous cell envelope structures found on members of nearly all taxonomic groups of bacteria and Archaea . They are composed of numerous identical subunits forming a symmetric, porous, lattice-like layer that completely covers the cell surface. The subunits are held together and attached to cell wall carbohydrates by non-covalent interactions, and they spontaneously reassemble in vitro by an entropy-driven process. Due to the low amino acid sequence similarity among S-layer proteins in general, verification of the presence of an S-layer on the bacterial cell surface usually requires electron microscopy. In lactobacilli, S-layer proteins have been detected on many but not all species. Lactobacillus S-layer proteins differ from those of other bacteria in their smaller size and high predicted p I . The positive charge in Lactobacillus S-layer proteins is concentrated in the more conserved cell wall binding domain, which can be either N- or C-terminal depending on the species. The more variable domain is responsible for the self-assembly of the monomers to a periodic structure. The biological functions of Lactobacillus S-layer proteins are poorly understood, but in some species S-layer proteins mediate bacterial adherence to host cells or extracellular matrix proteins or have protective or enzymatic functions. Lactobacillus S-layer proteins show potential for use as antigen carriers in live oral vaccine design because of their adhesive and immunomodulatory properties and the general non-pathogenicity of the species.

• Publisher: Springer-Verlag,Springer,Springer Nature B.V
• Subject: amino acid sequences / Amino acids / Analysis / Archaea / Bacteria / Bacterial Adhesion / Binding sites / Biomedical and Life Sciences / Biotechnology / Biotechnology - methods / Carbohydrates / Cell Surface Display Techniques / Cell Surface Display Techniques - methods / cell walls / Cellular biology / electron microscopy / Enzymes / extracellular matrix / Gene expression / genetics / Genomes / Isoelectric Point / Lactobacillus / Lactobacillus - genetics / Lactobacillus - metabolism / Life Sciences / Membrane Glycoproteins / Membrane Glycoproteins - genetics / Membrane Glycoproteins - metabolism / metabolism / methods / Microbial Genetics and Genomics / Microbiology / Microscopy / Mini-Review / Molecular Weight / Pathogens / Protein Interaction Domains and Motifs / Protein Multimerization / Proteins / Studies / Vaccines