The molecular architecture of Lactobacillus S-layer: Assembly and attachment to teichoic acids
Significance S-layer proteins (SLPs) are self-assembling, crystalline proteins coating the cell surfaces of many prokaryotes. This study presents experimental atomic resolution structures of lactobacilli SLPs, deriving functional insight into key probiotic Lactobacillus strains. The structures of SlpA and SlpX proteins highlight the domain swapping critical for SlpX integration, particularly in response to environmental stress. Two binding regions are identified as crucial for attachment of the S-layer to (lipo)teichoic acid. The structure of assembled S-layer provides a foundation for employing (designed) SLPs as a therapeutic agent in the treatment of inflammatory diseases. Additionally, it opens broad avenues for the use of SLPs in vaccine development and in crafting nanostructures with tailored properties, including those designed for targeted drug delivery.