Structural characterization of PSMa1 functional amyloids in Staphylococcus aureus biofilm

Abstract

Biofilm formation is a major problem for hospitals, particularly on medical device implants, because bacteria are enveloped in a protective extracellular matrix (ECM) that is resistant to degradation by existing antibiotics. Staphylococcus aureus accounts for most nosocomial-derived biofilm formation. Of the components of S. aureus biofilm are phenol-soluble modulins (PSMs), small peptides whose function depends upon their state of aggregation. As monomeric peptides, PSMs are toxic virulence factors; as aggregated fibers with amyloid structure, PSMs function as structural enhancers of the biofilm ECM and are appropriately termed functional amyloids.