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The crystal structure of pertussis toxin
P E Stein1, A Boodhoo, G D Armstrong
1Department of Medical Microbiology and Infectious Diseases, University of Alberta, Edmonton, Canada.
Structure (London, England : 1993)
|January 15, 1994
Summary
The crystal structure of pertussis toxin reveals its A-B exotoxin mechanism and subunit interactions. This finding aids in developing safer acellular vaccines for whooping cough and understanding toxin evolution.
Area of Science:
- Structural biology
- Bacteriology
- Immunology
Background:
- Pertussis toxin, an A-B exotoxin from Bordetella pertussis, is crucial for whooping cough immunity and acellular vaccines.
- It functions as a biochemical tool for studying signal transduction via ADP-ribosylation of GTP-binding proteins.
Purpose of the Study:
- To determine the crystal structure of pertussis toxin.
- To elucidate the structural basis for its pathogenic mechanisms and evolution.
- To inform the design of modified toxins for vaccine development.
Main Methods:
- X-ray crystallography at 2.9 A resolution.
Main Results:
- The catalytic A-subunit (S1) shows homology to other ADP-ribosylating toxins, with unique features in its C-terminal region.
- The B-oligomer (S2, S3, S4x2, S5) shares structural resemblance to cholera and Shiga toxin B-pentamers, despite low sequence homology.
- Unique domains in the B-oligomer exhibit homology to eukaryotic lectins, suggesting potential receptor-binding sites.
Conclusions:
- The determined structure offers insights into pertussis toxin's pathogenicity and bacterial toxin evolution.
- Understanding the active site's tertiary structure provides a foundation for creating catalytically inactive recombinant molecules for vaccines.