The Role of LPxTG Motif Proteins in Lactic Acid Bacteria: Unveiling Key Domains for Adhesion and Biofilm Formation

Cell surface LPxTG motif protein (LMP) plays a crucial role in adhesion and biofilm formation during lactic acid bacteria (LAB) colonization. LMP anchors to the cell wall via its C-terminal LPxTG motif and contains functional domains that perform specific tasks. By integrating bioinformatics analysis with existing literature, this review systematically evaluates, for the first time at the domain level, the diversity of LMP in LAB and constructs a functional domain framework for understanding their roles in adhesion and biofilm formation. Annotation analysis reveals domain diversity across LAB strains: mucin-binding and extracellular-matrix-binding domains are widespread, while others exhibit strain-specific characteristics. We also speculate that certain LMP domains may form pilus-like adhesion structures via sortase C-mediated polymerization. Overall, this domain-level elucidation of LMP probiotic mechanisms provides a theoretical basis for probiotic strain screening and functional optimization, and offers new insights into structural and functional localization of LMP on the LAB surface.