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A61 Large RNA genomes: Is RNA polymerase fidelity enough?
Large-genome Nidoviruses and Nidovirus-like viruses reside at the current boundary of largest RNA genome sizes. They code for an unusually large number of gene products matching that of small DNA viruses (e.g. DNA bacteriophages). The order of appearance and distribution of enzyme genes along variou...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6735827/ http://dx.doi.org/10.1093/ve/vez002.060 |
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author | Ferron, F Canard, B |
author_facet | Ferron, F Canard, B |
author_sort | Ferron, F |
collection | PubMed |
description | Large-genome Nidoviruses and Nidovirus-like viruses reside at the current boundary of largest RNA genome sizes. They code for an unusually large number of gene products matching that of small DNA viruses (e.g. DNA bacteriophages). The order of appearance and distribution of enzyme genes along various virus families (e.g. helicase and ExoN) may be seen as an evolutionary marker in these large RNA genomes lying at the genome size boundary. A positive correlation exists between (+)RNA virus genome sizes and the presence of the RNA helicase and the ExoN domains. Although the mechanistic basis of the presence of the helicase is still unclear, the role of the ExoN activity has been linked to the existence of an RNA synthesis proofreading system. In large Nidovirales, ExoN is bound to a processive replicative RNA-dependent RNA polymerase (RdRp) and corrects mismatched bases during viral RNA synthesis. Over the last decade, a view of the overall process has been refined in Coronaviruses, and in particular in our lab (Ferron et al., PNAS, 2018). We have identified genetic markers of large RNA genomes that we wish to use to data-mine currently existing metagenomic datasets. We have also initiated a collaboration to sequence and explore new viromes that will be searched according to these criteria. Likewise, we have a collection of purified viral RdRps that are currently being used to generate RNA synthesis products that will be compared to existing NGS datasets of cognate viruses. We will be able to have an idea about how much genetic diversity is possibly achievable by viral RdRp (‘tunable fidelity’) versus the detectable diversity (i.e. after selection in the infected cell) that is actually produced. |
format | Online Article Text |
id | pubmed-6735827 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-67358272019-09-16 A61 Large RNA genomes: Is RNA polymerase fidelity enough? Ferron, F Canard, B Virus Evol Abstract Overview Large-genome Nidoviruses and Nidovirus-like viruses reside at the current boundary of largest RNA genome sizes. They code for an unusually large number of gene products matching that of small DNA viruses (e.g. DNA bacteriophages). The order of appearance and distribution of enzyme genes along various virus families (e.g. helicase and ExoN) may be seen as an evolutionary marker in these large RNA genomes lying at the genome size boundary. A positive correlation exists between (+)RNA virus genome sizes and the presence of the RNA helicase and the ExoN domains. Although the mechanistic basis of the presence of the helicase is still unclear, the role of the ExoN activity has been linked to the existence of an RNA synthesis proofreading system. In large Nidovirales, ExoN is bound to a processive replicative RNA-dependent RNA polymerase (RdRp) and corrects mismatched bases during viral RNA synthesis. Over the last decade, a view of the overall process has been refined in Coronaviruses, and in particular in our lab (Ferron et al., PNAS, 2018). We have identified genetic markers of large RNA genomes that we wish to use to data-mine currently existing metagenomic datasets. We have also initiated a collaboration to sequence and explore new viromes that will be searched according to these criteria. Likewise, we have a collection of purified viral RdRps that are currently being used to generate RNA synthesis products that will be compared to existing NGS datasets of cognate viruses. We will be able to have an idea about how much genetic diversity is possibly achievable by viral RdRp (‘tunable fidelity’) versus the detectable diversity (i.e. after selection in the infected cell) that is actually produced. Oxford University Press 2019-08-22 /pmc/articles/PMC6735827/ http://dx.doi.org/10.1093/ve/vez002.060 Text en © Published by Oxford University Press. http://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access publication distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
spellingShingle | Abstract Overview Ferron, F Canard, B A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title | A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title_full | A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title_fullStr | A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title_full_unstemmed | A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title_short | A61 Large RNA genomes: Is RNA polymerase fidelity enough? |
title_sort | a61 large rna genomes: is rna polymerase fidelity enough? |
topic | Abstract Overview |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6735827/ http://dx.doi.org/10.1093/ve/vez002.060 |
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