Mapping CD55 function. The structure of two pathogen-binding domains at 1.7 A

J Biol Chem. 2003 Mar 21;278(12):10691-6. doi: 10.1074/jbc.M212561200. Epub 2002 Dec 22.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Adhesion
  • Binding Sites
  • CD55 Antigens / chemistry*
  • CD55 Antigens / physiology
  • CHO Cells
  • Complement Activation
  • Cricetinae
  • Crystallography, X-Ray
  • Humans
  • Receptors, Virus / chemistry
  • Receptors, Virus / physiology
  • Recombinant Proteins / chemistry


  • CD55 Antigens
  • Receptors, Virus
  • Recombinant Proteins

Associated data

  • PDB/1H03
  • PDB/1H03SF
  • PDB/1H04
  • PDB/1H2P
  • PDB/1H2Q