Bacterial surface protein

Bacterial surface proteins, especially S-layer proteins, form a crystalline, proteinaceous layer on the outer surface of many bacteria and archaea, composed of identical protein or glycoprotein subunits that self-assemble into a two-dimensional lattice. This layer serves as the outermost interface with the environment and is involved in diverse functions, including maintaining cell shape and integrity, acting as a molecular sieve, providing protection against environmental stresses and host immune defenses, facilitating adhesion, and mediating interactions with host cells. In pathogenic bacteria, S-layer proteins can be virulence factors by aiding in immune evasion and host colonization. In probiotic species, they may contribute to host health by excluding pathogens and stimulating immune responses. These proteins are of interest for biotechnological and medical applications, including vaccine development and diagnostics, due to their regularity, stability, and surface exposure. The molecular architecture and function of bacterial surface proteins vary widely among species, and their study is complicated by the diversity and complexity of these molecules.

Other names

S-layer proteinSurface layer protein (SLP)S-layer (glyco)proteinCell wall proteinExtracellular proteinBacterial cell surface protein