A subfamily of Dr adhesins of Escherichia coli bind independently to decay-accelerating factor and the N-domain of carcinoembryonic antigen.
J Biol Chem
; 281(39): 29120-30, 2006 Sep 29.
Article
em En
| MEDLINE
| ID: mdl-16882658
ABSTRACT
Escherichia coli expressing the Dr family of adhesins adheres to epithelial cells by binding to decay-accelerating factor (DAF) and carcinoembryonic antigen (CEA)-related cell surface proteins. The attachment of bacteria expressing Dr adhesins to DAF induces clustering of DAF around bacterial cells and also recruitment of CEA-related cell adhesion molecules. CEA, CEACAM1, and CEACAM6 have been shown to serve as receptors for some Dr adhesins (AfaE-I, AfaE-III, DraE, and DaaE). We demonstrate that AfaE-I, AfaE-V, DraE, and DaaE adhesins bind to the N-domain of CEA. To identify the residues involved in the N-CEA/DraE interaction, we performed SPR binding analyses of naturally occurring variants and a number of randomly generated mutants in DraE and N-CEA. Additionally, we used chemical shift mapping by NMR to determine the surface of DraE involved in N-CEA binding. These results show a distinct CEA binding site located primarily in the A, B, E, and D strands of the Dr adhesin. Interestingly, this site is located opposite to the beta-sheet encompassing the previously determined binding site for DAF, which implies that the adhesin can bind simultaneously to both receptors on the epithelial cell surface. The recognition of CEACAMs from a highly diverse DrCEA subfamily of Dr adhesins indicates that interaction with these receptors plays an important role in niche adaptation of E. coli strains expressing Dr adhesins.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Antígeno Carcinoembrionário
/
Adesinas Bacterianas
/
Antígenos CD55
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Escherichia coli
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article