Academic Journal
Genetic economy in picornaviruses: Foot-and-mouth disease virus replication exploits alternative precursor cleavage pathways.
| العنوان: | Genetic economy in picornaviruses: Foot-and-mouth disease virus replication exploits alternative precursor cleavage pathways. |
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| المؤلفون: | Morgan R Herod, Sarah Gold, Lidia Lasecka-Dykes, Caroline Wright, Joseph C Ward, Thomas C McLean, Sophie Forrest, Terry Jackson, Tobias J Tuthill, David J Rowlands, Nicola J Stonehouse |
| المصدر: | PLoS Pathogens, Vol 13, Iss 10, p e1006666 (2017) |
| بيانات النشر: | Public Library of Science (PLoS), 2017. |
| سنة النشر: | 2017 |
| المجموعة: | LCC:Immunologic diseases. Allergy LCC:Biology (General) |
| مصطلحات موضوعية: | Immunologic diseases. Allergy, RC581-607, Biology (General), QH301-705.5 |
| الوصف: | The RNA genomes of picornaviruses are translated into single polyproteins which are subsequently cleaved into structural and non-structural protein products. For genetic economy, proteins and processing intermediates have evolved to perform distinct functions. The picornavirus precursor protein, P3, is cleaved to produce membrane-associated 3A, primer peptide 3B, protease 3Cpro and polymerase 3Dpol. Uniquely, foot-and-mouth disease virus (FMDV) encodes three similar copies of 3B (3B1-3), thus providing a convenient natural system to explore the role(s) of 3B in the processing cascade. Using a replicon system, we confirmed by genetic deletion or functional inactivation that each copy of 3B appears to function independently to prime FMDV RNA replication. However, we also show that deletion of 3B3 prevents replication and that this could be reversed by introducing mutations at the C-terminus of 3B2 that restored the natural sequence at the 3B3-3C cleavage site. In vitro translation studies showed that precursors with 3B3 deleted were rapidly cleaved to produce 3CD but that no polymerase, 3Dpol, was detected. Complementation assays, using distinguishable replicons bearing different inactivating mutations, showed that replicons with mutations within 3Dpol could be recovered by 3Dpol derived from "helper" replicons (incorporating inactivation mutations in all three copies of 3B). However, complementation was not observed when the natural 3B-3C cleavage site was altered in the "helper" replicon, again suggesting that a processing abnormality at this position prevented the production of 3Dpol. When mutations affecting polyprotein processing were introduced into an infectious clone, viable viruses were recovered but these had acquired compensatory mutations in the 3B-3C cleavage site. These mutations were shown to restore the wild-type processing characteristics when analysed in an in vitro processing assay. Overall, this study demonstrates a dual functional role of the small primer peptide 3B3, further highlighting how picornaviruses increase genetic economy. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1553-7366 1553-7374 |
| Relation: | https://doaj.org/toc/1553-7366; https://doaj.org/toc/1553-7374 |
| DOI: | 10.1371/journal.ppat.1006666 |
| URL الوصول: | https://doaj.org/article/f00aa72db3d24648882e712bc8e4d3ea |
| رقم الانضمام: | edsdoj.f00aa72db3d24648882e712bc8e4d3ea |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 15537366 15537374 |
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| DOI: | 10.1371/journal.ppat.1006666 |