Display Settings:

Format

Send to:

Choose Destination
Protein Sci. 2007 Dec;16(12):2677-83.

Characterization of the binding surface of the translocated intimin receptor, an essential protein for EPEC and EHEC cell adhesion.

Author information

  • 1Department of Biochemistry and Biophysics and the Center for Future Health, University of Rochester, Rochester, New York 14642, USA.

Abstract

The translocated intimin receptor (TIR) of enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) is required for EPEC and EHEC infections, which cause widespread illness across the globe. TIR is translocated via a type-III secretion system into the intestinal epithelial cell membrane, where it serves as an anchor for E. coli attachment via its binding partner intimin. While many aspects of EPEC and EHEC infection are now well understood, the importance of the intermolecular contacts made between intimin and TIR have not been thoroughly investigated. Herein we report site-directed mutagenesis studies on the intimin-binding domain of EPEC TIR, and how these mutations affect TIR-intimin association, as analyzed by isothermal titration calorimetry and circular dichroism. These results show how two factors govern TIR's binding to intimin: A three-residue TIR hot spot is identified that largely mediates the interaction, and mutants that alter the beta-hairpin structure of TIR severely diminish binding affinity. In addition, peptides incorporating key TIR residues identified by mutagenesis are incapable of binding intimin. These results indicate that hot spot residues and structural orientation/preorganization are required for EPEC, and likely EHEC, TIR-intimin binding.

PMID:
18029421
[PubMed - indexed for MEDLINE]
PMCID:
PMC2222828
Free PMC Article

Images from this publication.See all images (3)Free text

Figure 1.
Figure 2.
Figure 3.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for John Wiley & Sons, Inc. Icon for PubMed Central
    Loading ...
    Write to the Help Desk