The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Mutational analysis of receptor binding mediated by the Dr family of Escherichia coli adhesins.

The fimbrial and afimbrial adhesins of the Dr family mediate the adherence of uropathogenic and diarrhoea-associated Escherichia coli to decay-accelerating factor (DAF) present on erythrocytes and other cell types. The Dr haemagglutinin binds type IV collagen and, unlike other members of the Dr family, mediates an adherence inhibited in the presence of chloramphenicol. We examined the ability of other members of the Dr family-AFAI, AFAIII, and F1845-to bind to type IV collagen, and demonstrated that the collagen-binding phenotype was unique to the Dr haemagglutinin. We employed site-directed mutagenesis to demonstrate the requirement of a negatively charged amino-acid at position 54 of the Dr haemagglutinin subunit for chloramphenicol sensitivity of binding. Mutations at position 32, 40, 54, 90, and 113 differently affected type IV collagen binding and chloramphenicol sensitivity of binding, while retaining DAF-binding capability. These results suggest the existence of a conformational receptor-binding domain in the major structural subunit of Dr family adhesins and demonstrate that chloramphenicol sensitivity of binding and adherence to type IV collagen were independent and separable phenotypes. Finally, we showed that the two conserved cysteine residues of Dr family structural subunits form a disulphide bond and that mutations of these residues abolish haemagglutination and binding to type IV collagen.[1]

References

 
WikiGenes - Universities