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Binding of intimin from enteropathogenic Escherichia coli to Tir and to host cells
Author(s) -
Hartland Elizabeth L.,
Batchelor Miranda,
Delahay Robin M.,
Hale Christine,
Matthews Stephen,
Dougan Gordon,
Knutton Stuart,
Connerton Ian,
Frankel Gad
Publication year - 1999
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1999.01338.x
Subject(s) - intimin , biology , escherichia coli , bacterial outer membrane , enteropathogenic escherichia coli , bacterial adhesin , microbiology and biotechnology , enterobacteriaceae , biochemistry , gene
Enteropathogenic Escherichia coli (EPEC) induce characteristic attaching and effacing (A/E) lesions on epithelial cells. This event is mediated, in part, by binding of the bacterial outer membrane protein, intimin, to a second EPEC protein, Tir (translocated intimin receptor), which is exported by the bacteria and integrated into the host cell plasma membrane. In this study, we have localized the intimin‐binding domain of Tir to a central 107‐amino‐acid region, designated Tir‐M. We provide evidence that both the amino‐ and carboxy‐termini of Tir are located within the host cell. In addition, using immunogold labelling electron microscopy, we have confirmed that intimin can bind independently to host cells even in the absence of Tir. This Tir‐independent interaction and the ability of EPEC to induce A/E lesions requires an intact lectin‐like module residing at the carboxy‐terminus of the intimin polypeptide. Using the yeast two‐hybrid system and gel overlays, we show that intimin can bind both Tir and Tir‐M even when the lectin‐like domain is disrupted. These data provide strong evidence that intimin interacts not only with Tir but also in a lectin‐like manner with a host cell intimin receptor.