Surface layer protein A (SlpA) (SlpA)

Surface layer protein A (SlpA) is the primary constituent of the paracrystalline S-layer that coats the cell surface of the Gram-positive pathogen Clostridioides difficile (UniProt P0C1S0). It is synthesized as a single precursor protein that is post-translationally cleaved by the protease Cwp84 into two subunits: a highly conserved High Molecular Weight (HMW) subunit and a highly variable, immunodominant Low Molecular Weight (LMW) subunit (Péchiné et al., 2018). The SLCT-4 variant represents a specific S-layer cassette type, one of several genetically distinct forms that contribute to the diversity of C. difficile strains, such as the toxin-variant ribotype 017 (Dingle et al., 2013). SlpA plays a critical role in bacterial fitness by mediating adhesion to host intestinal epithelial cells and contributing to immune evasion by forming a protective barrier (Kirk et al., 2017). As a surface-exposed protein essential for colonization and pathogenesis, it is a major target for the development of vaccines and monoclonal antibodies aimed at preventing or treating C. difficile infections. However, the significant sequence variation between different SLCT types poses a challenge for the development of broadly effective therapeutics (Dingle et al., 2013).

Other names

S-layer protein ASlpA precursorLMW-SLPHMW-SLPSLCT-4 variant SlpA

Inhibition of bacterial adhesion to host intestinal cells and enhancement of opsonophagocytosis