Trimeric autotransporter adhesins (TAAs) are important virulence factors of many Gram-
negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell
surface. Their N-terminal extracellular domains are exported through a C-terminal
membrane pore; the insertion of the pore domain into the bacterial outer membrane follows
the rules of β-barrel transmembrane protein biogenesis and is dependent on the essential
Bam complex. We have recently described the full fiber structure of SadA, a TAA of unknown …