YuaB functions synergistically with the exopolysaccharide and TasA amyloid fibers to allow biofilm formation by Bacillus subtilis.

During biofilm formation by Bacillus subtilis, two extracellular matrix components are synthesized, namely, the TasA amyloid fibers and an exopolysaccharide. In addition, a small protein called YuaB has been shown to allow the biofilm to form. The regulatory protein DegU is known to initiate biofilm formation.