Table 1.

Functions of surface-associated proteins.

Protein	Ligands	Role in biofilm formation
SdrF	A and B domains bind collagen	Adhesion to collagen deposited on ex vivo biomaterial Adhesion to abiotic surfaces
SdrG/Fbe	A domain binds fibrinogen	Promotes adhesion to conditioned biomaterial
Aap	None reported. G5-E repeats engage in homophilic interactions	Adhesion to abiotic surfaces via A domain. Cell-cell accumulation. Amyloid formation in mature biofilm.
Embp	FIVAR and FIVAR-GA domains bind fibronectin	Adhesion to conditioned biomaterial? FIVAR-GA region binds unknown ligand(s) on adjacent cells to promote accumulation
SdrC	Not known	Biofilm formation by unknown mechanism
SesJ	Plasminogen	Not known
SesI	Not known	Might promote adhesion to abiotic surfaces. Otherwise unknown
Geh	Collagen	Pure Geh binds collagen in vitro. Bacterial adhesion to immobilized collagen not tested
AtlE	Autolysin Recombinant protein binds vitronectin, fibronectin and fibrinogen in vitro	Release of e-DNA promotes adhesion to abiotic surfaces Adhesion to conditioned biomaterial?
Sbp	Secreted protein. Associated with cell wall. Possibly binds Aap	Amyloid formation contributes to biofilm integrity

SdrF, SdrG/Fbe, Aap, Embp, SdrC, SesJ, and SesI are anchored covalently to peptidoglycan by sortase.