The staphylococcal alpha-toxin pore has a flexible conformation.
The alpha-toxin from Staphylococcus aureus undergoes several conformational changes from the time it is released from the bacterium to the moment it forms a channel in the plasma membrane of its target cell. It is initially a soluble monomer, which undergoes membrane binding and oligomerization into...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
1999
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| _version_ | 1797060592579641344 |
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| author | Vécsey-Semjén, B Knapp, S Möllby, R van der Goot, F |
| author_facet | Vécsey-Semjén, B Knapp, S Möllby, R van der Goot, F |
| author_sort | Vécsey-Semjén, B |
| collection | OXFORD |
| description | The alpha-toxin from Staphylococcus aureus undergoes several conformational changes from the time it is released from the bacterium to the moment it forms a channel in the plasma membrane of its target cell. It is initially a soluble monomer, which undergoes membrane binding and oligomerization into a heptameric ring and finally inserts into the lipid bilayer to form a pore. Here we have analyzed the stability of different forms of the alpha-toxin (monomer as well as heptamers in solution, bound to the membrane and membrane-inserted) by differential scanning calorimetry and limited proteolysis. Data presented here show that, in contrast to both the membrane-bound prepore complex and the monomer in solution, the membrane-inserted alpha-toxin channel does not undergo cooperative unfolding and is highly susceptible to proteases. These observations suggest that the channel has a looser conformation. Interestingly, resistance to proteases could be recovered upon solubilization of the channel, indicating that the loss of rigid tertiary packing only occurred upon membrane insertion. Far-UV CD data, however, suggest that the transmembrane beta-barrel must be stably folded and that therefore only the Cap and Rim domains of the channel are loosely packed. All together, our data show that the alpha-toxin channel is not a rigid complex within the membrane but adopts a rather flexible conformation. |
| first_indexed | 2024-03-06T20:19:16Z |
| format | Journal article |
| id | oxford-uuid:2d3d6313-65c9-4109-93d3-3b7774fe4572 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:19:16Z |
| publishDate | 1999 |
| record_format | dspace |
| spelling | oxford-uuid:2d3d6313-65c9-4109-93d3-3b7774fe45722022-03-26T12:41:40ZThe staphylococcal alpha-toxin pore has a flexible conformation.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2d3d6313-65c9-4109-93d3-3b7774fe4572EnglishSymplectic Elements at Oxford1999Vécsey-Semjén, BKnapp, SMöllby, Rvan der Goot, FThe alpha-toxin from Staphylococcus aureus undergoes several conformational changes from the time it is released from the bacterium to the moment it forms a channel in the plasma membrane of its target cell. It is initially a soluble monomer, which undergoes membrane binding and oligomerization into a heptameric ring and finally inserts into the lipid bilayer to form a pore. Here we have analyzed the stability of different forms of the alpha-toxin (monomer as well as heptamers in solution, bound to the membrane and membrane-inserted) by differential scanning calorimetry and limited proteolysis. Data presented here show that, in contrast to both the membrane-bound prepore complex and the monomer in solution, the membrane-inserted alpha-toxin channel does not undergo cooperative unfolding and is highly susceptible to proteases. These observations suggest that the channel has a looser conformation. Interestingly, resistance to proteases could be recovered upon solubilization of the channel, indicating that the loss of rigid tertiary packing only occurred upon membrane insertion. Far-UV CD data, however, suggest that the transmembrane beta-barrel must be stably folded and that therefore only the Cap and Rim domains of the channel are loosely packed. All together, our data show that the alpha-toxin channel is not a rigid complex within the membrane but adopts a rather flexible conformation. |
| spellingShingle | Vécsey-Semjén, B Knapp, S Möllby, R van der Goot, F The staphylococcal alpha-toxin pore has a flexible conformation. |
| title | The staphylococcal alpha-toxin pore has a flexible conformation. |
| title_full | The staphylococcal alpha-toxin pore has a flexible conformation. |
| title_fullStr | The staphylococcal alpha-toxin pore has a flexible conformation. |
| title_full_unstemmed | The staphylococcal alpha-toxin pore has a flexible conformation. |
| title_short | The staphylococcal alpha-toxin pore has a flexible conformation. |
| title_sort | staphylococcal alpha toxin pore has a flexible conformation |
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