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Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA

Viral genomic RNA is packaged into virions with high specificity and selectivity. However, in vitro the Gag specificity towards viral RNA is obscured when measured in buffers containing physiological salt. Interestingly, when the binding is challenged by increased salt concentration, the addition of...

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Detalles Bibliográficos
Autores principales: Kroupa, Tomas, Datta, Siddhartha A. K., Rein, Alan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232488/
https://www.ncbi.nlm.nih.gov/pubmed/32252233
http://dx.doi.org/10.3390/v12040394
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author Kroupa, Tomas
Datta, Siddhartha A. K.
Rein, Alan
author_facet Kroupa, Tomas
Datta, Siddhartha A. K.
Rein, Alan
author_sort Kroupa, Tomas
collection PubMed
description Viral genomic RNA is packaged into virions with high specificity and selectivity. However, in vitro the Gag specificity towards viral RNA is obscured when measured in buffers containing physiological salt. Interestingly, when the binding is challenged by increased salt concentration, the addition of competing RNAs, or introducing mutations to Gag protein, the specificity towards viral RNA becomes detectable. The objective of this work was to examine the contributions of the individual HIV-1 Gag polyprotein domains to nonspecific and specific RNA binding and stability of the initial protein-RNA complexes. Using a panel of Gag proteins with mutations disabling different Gag-Gag or Gag-RNA interfaces, we investigated the distinct contributions of individual domains which distinguish the binding to viral and nonviral RNA by measuring the binding of the proteins to RNAs. We measured the binding affinity in near-physiological salt concentration, and then challenged the binding by increasing the ionic strength to suppress the electrostatic interactions and reveal the contribution of specific Gag–RNA and Gag–Gag interactions. Surprisingly, we observed that Gag dimerization and the highly basic region in the matrix domain contribute significantly to the specificity of viral RNA binding.
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spelling pubmed-72324882020-05-22 Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA Kroupa, Tomas Datta, Siddhartha A. K. Rein, Alan Viruses Article Viral genomic RNA is packaged into virions with high specificity and selectivity. However, in vitro the Gag specificity towards viral RNA is obscured when measured in buffers containing physiological salt. Interestingly, when the binding is challenged by increased salt concentration, the addition of competing RNAs, or introducing mutations to Gag protein, the specificity towards viral RNA becomes detectable. The objective of this work was to examine the contributions of the individual HIV-1 Gag polyprotein domains to nonspecific and specific RNA binding and stability of the initial protein-RNA complexes. Using a panel of Gag proteins with mutations disabling different Gag-Gag or Gag-RNA interfaces, we investigated the distinct contributions of individual domains which distinguish the binding to viral and nonviral RNA by measuring the binding of the proteins to RNAs. We measured the binding affinity in near-physiological salt concentration, and then challenged the binding by increasing the ionic strength to suppress the electrostatic interactions and reveal the contribution of specific Gag–RNA and Gag–Gag interactions. Surprisingly, we observed that Gag dimerization and the highly basic region in the matrix domain contribute significantly to the specificity of viral RNA binding. MDPI 2020-04-02 /pmc/articles/PMC7232488/ /pubmed/32252233 http://dx.doi.org/10.3390/v12040394 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Kroupa, Tomas
Datta, Siddhartha A. K.
Rein, Alan
Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title_full Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title_fullStr Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title_full_unstemmed Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title_short Distinct Contributions of Different Domains within the HIV-1 Gag Polyprotein to Specific and Nonspecific Interactions with RNA
title_sort distinct contributions of different domains within the hiv-1 gag polyprotein to specific and nonspecific interactions with rna
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232488/
https://www.ncbi.nlm.nih.gov/pubmed/32252233
http://dx.doi.org/10.3390/v12040394
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