Mapping CD55 function: the structure of two pathogen-binding domains at 1.7 A

Williams, P., Chaudhry, Y., Goodfellow, I. G., Billington, J., Powell, R., Spiller, O. B., Evans, D. J. and Lea, S. (2003) Mapping CD55 function: the structure of two pathogen-binding domains at 1.7 A. The Journal of Biological Chemistry, 278 (12). pp. 10691-6. ISSN 1083-351X doi: 10.1074/jbc.M212561200

Abstract/Summary

Decay-accelerating factor (CD55), a regulator of the alternative and classical pathways of complement activation, is expressed on all serum-exposed cells. It is used by pathogens, including many enteroviruses and uropathogenic Escherichia coli, as a receptor prior to infection. We describe the x-ray structure of a pathogen-binding fragment of human CD55 at 1.7 A resolution containing two of the three domains required for regulation of human complement. We have used mutagenesis to map biological functions onto the molecule; decay-accelerating activity maps to a single face of the molecule, whereas bacterial and viral pathogens recognize a variety of different sites on CD55.