THE INTERMOLECULAR FORCES THAT GOVERN THE FORMATION OF AMYLOID-LIKE FIBERS IN A BACTERIAL BIOFILM.

A biofilm is a group of microorganisms in which cells stick to each other on a surface. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The cells in a biofilm are embedded within a self-produced matrix of extracellular polymeric substance (EPS). The EPS is generally composed of extracellular DNA, proteins and polysaccharides. In biofilms of our model organism, the soil bacterium Bacillus subtilis, cells are held together by extracellular cell-anchored amyloid-like fibers that are composed primarily of the protein TasA. TasA has an accessory protein, TapA, that serves both to anchor the fibers to the cell wall and to assemble TasA into fibers. Despite the knowledge of the location of TapA in the biofilm, little is known about the mechanism of action of this protein. In particular, we are interested in studying the TapA-TasA interactions in order to better understand the role of TapA in the formation of the amyloid-like fibers. A molecular understanding of the assembly of the amyloid-like fibers may lead the way to developing new anti-biofilm drugs.