A structural basis for Staphylococcal complement subversion: X-ray structure of the complement-binding domain of Staphylococcus aureus protein Sbi in complex with ligand C3d.
Mol Immunol
; 48(4): 452-62, 2011 Jan.
Article
em En
| MEDLINE
| ID: mdl-21055811
ABSTRACT
The structure of the complement-binding domain of Staphylococcus aureus protein Sbi (Sbi-IV) in complex with ligand C3d is presented. The 1.7Å resolution structure reveals the molecular details of the recognition of thioester-containing fragment C3d of the central complement component C3, involving interactions between residues of Sbi-IV helix α2 and the acidic concave surface of C3d. The complex provides a structural basis for the binding preference of Sbi for native C3 over C3b and explains how Sbi-IV inhibits the interaction between C3d and complement receptor 2. A second C3d binding site on Sbi-IV is identified in the crystal structure that is not observed in related S. aureus C3 inhibitors Efb-C and Ehp. This binding mode perhaps hints as to how Sbi-IV, as part of Sbi, forms a C3b-Sbi adduct and causes futile consumption of C3, an extraordinary aspect of Sbi function that is not shared by any other known Staphylococcal complement inhibitor.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Staphylococcus aureus
/
Proteínas de Bactérias
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Proteínas de Transporte
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Complemento C3d
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article