3D imaging of the 58 kDa cell binding subunit of the Helicobacter pylori cytotoxin

Autor: Nathalie Norais, Cristina Ulivieri, Cristina Pagliaccia, John L. Telford, Marie Charrel, Véronique Cabiaux, Marina de Bernard, Jean-Marc Reyrat, Emanuele Papini, Salvatore Lanzavecchia, Pietro Lupetti, Vladimir Pelicic, Rino Rappuoli, Xuhuai Ji
Přispěvatelé: Immunobiological Research Institute of Siena, Partenaires INRAE, Universita degli Studi di Padova, Department of Life Sciences [Siena, Italy], Università degli Studi di Siena = University of Siena (UNISI)
Jazyk: angličtina
Rok vydání: 1999
Předmět:
Models
Molecular
Specificity factor
Plasma protein binding
medicine.disease_cause
law.invention
Structural Biology
law
toxin
ComputingMilieux_MISCELLANEOUS
Sequence Deletion
0303 health sciences
Cytotoxins
Freeze Etching
Vacuolating cytotoxin
VacA
Endocytosis
Recombinant Proteins
3. Good health
Biochemistry
Recombinant DNA
Dimerization
Protein Binding
Helicobacter pylori
Cell Survival
Protein subunit
Bacterial Toxins
Molecular Sequence Data
Biology
B-subunit
Cleavage (embryo)
03 medical and health sciences
Bacterial Proteins
3D reconstruction
Escherichia coli
medicine
Humans
Molecular Biology
030304 developmental biology
Molecular mass
030306 microbiology
[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Peptide Fragments
Molecular Weight
Microscopy
Electron
Solubility
Vacuoles
Exotoxin
HeLa Cells
Zdroj: Journal of Molecular Biology
Journal of Molecular Biology, Elsevier, 1999, 290 (2), pp.459-470. ⟨10.1006/jmbi.1999.2877⟩
ISSN: 0022-2836
1089-8638
DOI: 10.1006/jmbi.1999.2877⟩
Popis: Pathogenic strains of Helicobacter pylori produce a potent exotoxin, VacA, which intoxicates gastric epithelial cells and leads to peptic ulcer. The toxin is released from the bacteria as a high molecular mass homo-oligomer of a 95 kDa polypeptide which undergoes specific proteolytic cleavage to 37 kDa and 58 kDa subunits. We have engineered a strain of H. pylori to delete the gene sequence coding for the 37 kDa subunit. The remaining 58 kDa subunit is expressed efficiently and exported as a soluble dimer that is non-toxic but binds target cells in a manner similar to the holotoxin. A 3D reconstruction of the molecule from electron micrographs of quick-freeze, deep-etched preparations reveals the contribution of each building block to the structure and permits the reconstruction of the oligomeric holotoxin starting from individual subunits. In this model P58 subunits are assembled in a ring structure with P37 subunits laying on the top. The data indicate that the 58 kDa subunit is capable of folding autonomously into a discrete structure recognizable within the holotoxin and containing the cell binding domain.
Databáze: OpenAIRE
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