Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins.
Vaccinia virus interferes with early events of the activation pathway of the transcriptional factor NF-kB by binding to numerous host TIR-domain containing adaptor proteins. We have previously determined the X-ray structure of the A46 C-terminal domain; however, the structure and function of the A46...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2016-12-01
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| Series: | PLoS Pathogens |
| Online Access: | https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1006079&type=printable |
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| _version_ | 1850133329078124544 |
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| author | Sofiya Fedosyuk Gustavo Arruda Bezerra Katharina Radakovics Terry K Smith Massimo Sammito Nina Bobik Adam Round Lynn F Ten Eyck Kristina Djinović-Carugo Isabel Usón Tim Skern |
| author_facet | Sofiya Fedosyuk Gustavo Arruda Bezerra Katharina Radakovics Terry K Smith Massimo Sammito Nina Bobik Adam Round Lynn F Ten Eyck Kristina Djinović-Carugo Isabel Usón Tim Skern |
| author_sort | Sofiya Fedosyuk |
| collection | DOAJ |
| description | Vaccinia virus interferes with early events of the activation pathway of the transcriptional factor NF-kB by binding to numerous host TIR-domain containing adaptor proteins. We have previously determined the X-ray structure of the A46 C-terminal domain; however, the structure and function of the A46 N-terminal domain and its relationship to the C-terminal domain have remained unclear. Here, we biophysically characterize residues 1-83 of the N-terminal domain of A46 and present the X-ray structure at 1.55 Å. Crystallographic phases were obtained by a recently developed ab initio method entitled ARCIMBOLDO_BORGES that employs tertiary structure libraries extracted from the Protein Data Bank; data analysis revealed an all β-sheet structure. This is the first such structure solved by this method which should be applicable to any protein composed entirely of β-sheets. The A46(1-83) structure itself is a β-sandwich containing a co-purified molecule of myristic acid inside a hydrophobic pocket and represents a previously unknown lipid-binding fold. Mass spectrometry analysis confirmed the presence of long-chain fatty acids in both N-terminal and full-length A46; mutation of the hydrophobic pocket reduced the lipid content. Using a combination of high resolution X-ray structures of the N- and C-terminal domains and SAXS analysis of full-length protein A46(1-240), we present here a structural model of A46 in a tetrameric assembly. Integrating affinity measurements and structural data, we propose how A46 simultaneously interferes with several TIR-domain containing proteins to inhibit NF-κB activation and postulate that A46 employs a bipartite binding arrangement to sequester the host immune adaptors TRAM and MyD88. |
| format | Article |
| id | doaj-art-4120c21604904d6bbfde04d0e9cc44e4 |
| institution | OA Journals |
| issn | 1553-7366 1553-7374 |
| language | English |
| publishDate | 2016-12-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj-art-4120c21604904d6bbfde04d0e9cc44e42025-08-20T02:31:59ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742016-12-011212e100607910.1371/journal.ppat.1006079Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins.Sofiya FedosyukGustavo Arruda BezerraKatharina RadakovicsTerry K SmithMassimo SammitoNina BobikAdam RoundLynn F Ten EyckKristina Djinović-CarugoIsabel UsónTim SkernVaccinia virus interferes with early events of the activation pathway of the transcriptional factor NF-kB by binding to numerous host TIR-domain containing adaptor proteins. We have previously determined the X-ray structure of the A46 C-terminal domain; however, the structure and function of the A46 N-terminal domain and its relationship to the C-terminal domain have remained unclear. Here, we biophysically characterize residues 1-83 of the N-terminal domain of A46 and present the X-ray structure at 1.55 Å. Crystallographic phases were obtained by a recently developed ab initio method entitled ARCIMBOLDO_BORGES that employs tertiary structure libraries extracted from the Protein Data Bank; data analysis revealed an all β-sheet structure. This is the first such structure solved by this method which should be applicable to any protein composed entirely of β-sheets. The A46(1-83) structure itself is a β-sandwich containing a co-purified molecule of myristic acid inside a hydrophobic pocket and represents a previously unknown lipid-binding fold. Mass spectrometry analysis confirmed the presence of long-chain fatty acids in both N-terminal and full-length A46; mutation of the hydrophobic pocket reduced the lipid content. Using a combination of high resolution X-ray structures of the N- and C-terminal domains and SAXS analysis of full-length protein A46(1-240), we present here a structural model of A46 in a tetrameric assembly. Integrating affinity measurements and structural data, we propose how A46 simultaneously interferes with several TIR-domain containing proteins to inhibit NF-κB activation and postulate that A46 employs a bipartite binding arrangement to sequester the host immune adaptors TRAM and MyD88.https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1006079&type=printable |
| spellingShingle | Sofiya Fedosyuk Gustavo Arruda Bezerra Katharina Radakovics Terry K Smith Massimo Sammito Nina Bobik Adam Round Lynn F Ten Eyck Kristina Djinović-Carugo Isabel Usón Tim Skern Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. PLoS Pathogens |
| title | Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. |
| title_full | Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. |
| title_fullStr | Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. |
| title_full_unstemmed | Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. |
| title_short | Vaccinia Virus Immunomodulator A46: A Lipid and Protein-Binding Scaffold for Sequestering Host TIR-Domain Proteins. |
| title_sort | vaccinia virus immunomodulator a46 a lipid and protein binding scaffold for sequestering host tir domain proteins |
| url | https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1006079&type=printable |
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