Structural and biochemical characterization of the type III secretion chaperones CesT and SigE.
Nat Struct Biol
; 8(12): 1031-6, 2001 Dec.
Article
de En
| MEDLINE
| ID: mdl-11685226
ABSTRACT
Several Gram-negative bacterial pathogens have evolved a type III secretion system to deliver virulence effector proteins directly into eukaryotic cells, a process essential for disease. This specialized secretion process requires customized chaperones specific for particular effector proteins. The crystal structures of the enterohemorrhagic Escherichia coli O157H7 Tir-specific chaperone CesT and the Salmonella enterica SigD-specific chaperone SigE reveal a common overall fold and formation of homodimers. Site-directed mutagenesis suggests that variable, delocalized hydrophobic surfaces observed on the chaperone homodimers are responsible for specific binding to a particular effector protein. Isothermal titration calorimetry studies of Tir-CesT and enzymatic activity profiles of SigD-SigE indicate that the effector proteins are not globally unfolded in the presence of their cognate chaperones.
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Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Chaperons moléculaires
/
Salmonella enterica
/
Protéines Escherichia coli
Type d'étude:
Prognostic_studies
Langue:
En
Journal:
Nat Struct Biol
Sujet du journal:
BIOLOGIA MOLECULAR
Année:
2001
Type de document:
Article
Pays d'affiliation:
Canada