Figure 3.

Structural domains of c0139's product in the reannotation and autotransporter virulence factor antigen 43. The domain in blue has the ability to form a β-barrel, also termed autotransporter domain, and is a key component in self-exportation; the domain in green is the passenger domain, which varies widely with different ATs; the segment in red is signal peptide, which guides the whole protein during the translocation; and the dashed line indicates the cleavage site in which protease cuts AT and releases the passenger segment.