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A Nonoligomerizing Mutant Form of Helicobacter pylori VacA Allows Structural Analysis of the p33 Domain.
González-Rivera, Christian; Campbell, Anne M; Rutherford, Stacey A; Pyburn, Tasia M; Foegeding, Nora J; Barke, Theresa L; Spiller, Benjamin W; McClain, Mark S; Ohi, Melanie D; Lacy, D Borden; Cover, Timothy L.
Afiliación
  • González-Rivera C; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Campbell AM; Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Rutherford SA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Pyburn TM; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Foegeding NJ; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Barke TL; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Spiller BW; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • McClain MS; Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Ohi MD; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
  • Lacy DB; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA borden.lacy@vanderbilt.edu timothy.l.cover@vanderbilt.edu.
  • Cover TL; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA borden
Infect Immun ; 84(9): 2662-70, 2016 09.
Article en En | MEDLINE | ID: mdl-27382020
Helicobacter pylori secretes a pore-forming VacA toxin that has structural features and activities substantially different from those of other known bacterial toxins. VacA can assemble into multiple types of water-soluble flower-shaped oligomeric structures, and most VacA activities are dependent on its capacity to oligomerize. The 88-kDa secreted VacA protein can undergo limited proteolysis to yield two domains, designated p33 and p55. The p33 domain is required for membrane channel formation and intracellular toxic activities, and the p55 domain has an important role in mediating VacA binding to cells. Previous studies showed that the p55 domain has a predominantly ß-helical structure, but no structural data are available for the p33 domain. We report here the purification and analysis of a nonoligomerizing mutant form of VacA secreted by H. pylori The nonoligomerizing 88-kDa mutant protein retains the capacity to enter host cells but lacks detectable toxic activity. Analysis of crystals formed by the monomeric protein reveals that the ß-helical structure of the p55 domain extends into the C-terminal portion of p33. Fitting the p88 structural model into an electron microscopy map of hexamers formed by wild-type VacA (predicted to be structurally similar to VacA membrane channels) reveals that p55 and the ß-helical segment of p33 localize to peripheral arms but do not occupy the central region of the hexamers. We propose that the amino-terminal portion of p33 is unstructured when VacA is in a monomeric form and that it undergoes a conformational change during oligomer assembly.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Toxinas Bacterianas / Helicobacter pylori / Dominios Proteicos / Mutación Tipo de estudio: Prognostic_studies Límite: Humans Idioma: En Revista: Infect Immun Año: 2016 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
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XML
PubMed Links
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Toxinas Bacterianas / Helicobacter pylori / Dominios Proteicos / Mutación Tipo de estudio: Prognostic_studies Límite: Humans Idioma: En Revista: Infect Immun Año: 2016 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos