The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex.
The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5∶1∶1 stoichio...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS Pathogens |
| Online Access: | http://europepmc.org/articles/PMC3789776?pdf=render |
| _version_ | 1818529514363289600 |
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| author | Guowei Yang Nicholas R Waterfield |
| author_facet | Guowei Yang Nicholas R Waterfield |
| author_sort | Guowei Yang |
| collection | DOAJ |
| description | The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5∶1∶1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man. |
| first_indexed | 2024-12-11T17:07:51Z |
| format | Article |
| id | doaj.art-ffa932a96bdc49e18cf7005fd777796e |
| institution | Directory Open Access Journal |
| issn | 1553-7366 1553-7374 |
| language | English |
| last_indexed | 2024-12-11T17:07:51Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj.art-ffa932a96bdc49e18cf7005fd777796e2022-12-22T00:57:38ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742013-01-01910e100364410.1371/journal.ppat.1003644The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex.Guowei YangNicholas R WaterfieldThe Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5∶1∶1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man.http://europepmc.org/articles/PMC3789776?pdf=render |
| spellingShingle | Guowei Yang Nicholas R Waterfield The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. PLoS Pathogens |
| title | The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. |
| title_full | The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. |
| title_fullStr | The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. |
| title_full_unstemmed | The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. |
| title_short | The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex. |
| title_sort | role of tcdb and tccc subunits in secretion of the photorhabdus tcd toxin complex |
| url | http://europepmc.org/articles/PMC3789776?pdf=render |
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