Open AccessThe filamentous type III secretion translocon of enteropathogenic Escherichia coli
Author(s) -
Daniell Sarah J.,
Takahashi Noriko,
Wilson Rebecca,
Friedberg Devorah,
Rosenshine Ilan,
Booy Frank P.,
Shaw Robert K.,
Knutton Stuart,
Frankel Gad,
Aizawa ShinIchi
Publication year - 2001
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1046/j.1462-5822.2001.00168.x
Subject(s) - enteropathogenic escherichia coli , secretion , biology , effector , shigella , translocon , intimin , type three secretion system , microbiology and biotechnology , cytosol , bacterial outer membrane , escherichia coli , shigella flexneri , membrane protein , enterobacteriaceae , membrane , biochemistry , virulence , gene , enzyme
Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system (TTSS) to inject effector proteins into the plasma membrane and cytosol of infected cells. To translocate proteins, EPEC, like Salmonella and Shigella , is believed to assemble a macromolecular complex (type III secreton) that spans both bacterial membranes and has a short needle‐like projection. However, there is a special interest in studying the EPEC TTSS owing to the fact that one of the secreted proteins, EspA, is assembled into a unique filamentous structure also required for protein translocation. In this report we present electron micrographs of EspA filaments which reveal a regular segmented substructure. Recently we have shown that deletion of the putative structural needle protein, EscF, abolished protein secretion and formation of EspA filaments. Moreover, we demonstrated that EspA can bind directly to EscF, suggesting that EspA filaments are physically linked to the EPEC needle complex. In this paper we provide direct evidence for the association between an EPEC bacterial membrane needle complex and EspA filaments, defining a new class of filamentous TTSS.