Structure of the streptococcal endopeptidase IdeS, a cysteine proteinase with strict specificity for IgG.
Proc Natl Acad Sci U S A
; 101(50): 17371-6, 2004 Dec 14.
Article
em En
| MEDLINE
| ID: mdl-15574492
ABSTRACT
Pathogenic bacteria have developed complex and diverse virulence mechanisms that weaken or disable the host immune defense system. IdeS (IgG-degrading enzyme of Streptococcus pyogenes) is a secreted cysteine endopeptidase from the human pathogen S. pyogenes with an extraordinarily high degree of substrate specificity, catalyzing a single proteolytic cleavage at the lower hinge of human IgG. This proteolytic degradation promotes inhibition of opsonophagocytosis and interferes with the killing of group A Streptococcus. We have determined the crystal structure of the catalytically inactive mutant IdeS-C94S by x-ray crystallography at 1.9-A resolution. Despite negligible sequence homology to known proteinases, the core of the structure resembles the canonical papain fold although with major insertions and a distinct substrate-binding site. Therefore IdeS belongs to a unique family within the CA clan of cysteine proteinases. Based on analogy with inhibitor complexes of papain-like proteinases, we propose a model for substrate binding by IdeS.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Streptococcus pyogenes
/
Imunoglobulina G
/
Cisteína Endopeptidases
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Alemanha