Virulence functions of autotransporter proteins.

Bacterial pathogens must execute a prodigious array of complex functions in order to survive, multiply, and disseminate within mammalian hosts. Virulence determinants are usually proteinaceous in nature and are often either secreted to the bacterial cell surface or released into the external environment. Although secreted virulence proteins serve many divergent functions, remarkably, gram-negative bacteria have developed only a small number of secretion systems by which such proteins pass through their outer membranes. In this review, we discuss the virulence functions assigned or suspected for proteins secreted via the type V autotransporter pathway (Table 1).