TY - JOUR
T1 - Polarity of Enteropathogenic Escherichia coli EspA Filament Assembly and Protein Secretion
AU - Crepin, VF
AU - Shaw, Robert
AU - Abe, Cecilia
AU - Knutton, Stuart
AU - Frankel, G
PY - 2005/4/15
Y1 - 2005/4/15
N2 - Type III secretion systems (TTSS) are sophisticated macromolecular structures that play an imperative role in bacterial infections and human disease. The TTSS needle complex is conserved among bacterial pathogens and shows broad similarity to the flagellar basal body. However, the TTSS of enteropathogenic and enterohemorrhagic Escherichia coli, two important human enteric pathogens, is unique in that it has alpha similar to 12-nm-diameter filamentous extension to the needle that is composed of the secreted translocator protein EspA. EspA filaments and flagellar structures have very similar helical symmetry parameters. In this study we investigated EspA filament assembly and the delivery of effector proteins across the bacterial cell wall. We show that EspA filaments are elongated by addition of EspA subunits to the tip of the growing filament. Moreover, EspA filament length is modulated by the availability of intracellular EspA subunits. Finally, we provide direct evidence that EspA filaments are hollow conduits through which effector proteins are delivered to the extremity of the bacterial cell (and subsequently into the host cell).
AB - Type III secretion systems (TTSS) are sophisticated macromolecular structures that play an imperative role in bacterial infections and human disease. The TTSS needle complex is conserved among bacterial pathogens and shows broad similarity to the flagellar basal body. However, the TTSS of enteropathogenic and enterohemorrhagic Escherichia coli, two important human enteric pathogens, is unique in that it has alpha similar to 12-nm-diameter filamentous extension to the needle that is composed of the secreted translocator protein EspA. EspA filaments and flagellar structures have very similar helical symmetry parameters. In this study we investigated EspA filament assembly and the delivery of effector proteins across the bacterial cell wall. We show that EspA filaments are elongated by addition of EspA subunits to the tip of the growing filament. Moreover, EspA filament length is modulated by the availability of intracellular EspA subunits. Finally, we provide direct evidence that EspA filaments are hollow conduits through which effector proteins are delivered to the extremity of the bacterial cell (and subsequently into the host cell).
UR - http://www.scopus.com/inward/record.url?scp=16844376367&partnerID=8YFLogxK
U2 - 10.1128/JB.187.8.2881-2889.2005
DO - 10.1128/JB.187.8.2881-2889.2005
M3 - Article
C2 - 15805534
VL - 187
SP - 2881
EP - 2889
JO - Journal of Bacteriology
JF - Journal of Bacteriology
ER -