Regulation of coronavirus nsp15 cleavage specificity by RNA structure.

SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, has had an enduring impact on global public health. However, SARS-CoV-2 is only one of multiple pathogenic human coronaviruses (CoVs) to have emerged since the turn of the century. CoVs encode for several nonstructural proteins (nsps) that ar...

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Main Authors: Indraneel Salukhe, Ryan Choi, Wesley Van Voorhis, Lynn Barrett, Jennifer Hyde
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2023-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0290675
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author Indraneel Salukhe
Ryan Choi
Wesley Van Voorhis
Lynn Barrett
Jennifer Hyde
author_facet Indraneel Salukhe
Ryan Choi
Wesley Van Voorhis
Lynn Barrett
Jennifer Hyde
author_sort Indraneel Salukhe
collection DOAJ
description SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, has had an enduring impact on global public health. However, SARS-CoV-2 is only one of multiple pathogenic human coronaviruses (CoVs) to have emerged since the turn of the century. CoVs encode for several nonstructural proteins (nsps) that are essential for viral replication and pathogenesis. Among them is nsp15, a uridine-specific viral endonuclease that is important in evading the host immune response and promoting viral replication. Despite the established endonuclease function of nsp15, little is known about other determinants of its cleavage specificity. In this study we investigate the role of RNA secondary structure in SARS-CoV-2 nsp15 endonuclease activity. Using a series of in vitro endonuclease assays, we observed that thermodynamically stable RNA structures were protected from nsp15 cleavage relative to RNAs lacking stable structure. We leveraged the s2m RNA from the SARS-CoV-1 3'UTR as a model for our structural studies as it adopts a well-defined structure with several uridines, two of which are unpaired and thus highly probable targets for nsp15 cleavage. We found that SARS-CoV-2 nsp15 specifically cleaves s2m at the unpaired uridine within the GNRNA pentaloop of the RNA. Further investigation revealed that the position of uridine within the pentaloop also impacted nsp15 cleavage efficiency suggesting that positioning within the pentaloop is necessary for optimal presentation of the scissile uridine and alignment within the nsp15 catalytic pocket. Our findings indicate that RNA secondary structure is an important determinant of nsp15 cleavage and provides insight into the molecular mechanisms of RNA recognition by nsp15.
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spelling doaj.art-6e6b91ccfd0344ac8fffe536a424eedf2023-09-07T05:31:27ZengPublic Library of Science (PLoS)PLoS ONE1932-62032023-01-01188e029067510.1371/journal.pone.0290675Regulation of coronavirus nsp15 cleavage specificity by RNA structure.Indraneel SalukheRyan ChoiWesley Van VoorhisLynn BarrettJennifer HydeSARS-CoV-2, the etiologic agent of the COVID-19 pandemic, has had an enduring impact on global public health. However, SARS-CoV-2 is only one of multiple pathogenic human coronaviruses (CoVs) to have emerged since the turn of the century. CoVs encode for several nonstructural proteins (nsps) that are essential for viral replication and pathogenesis. Among them is nsp15, a uridine-specific viral endonuclease that is important in evading the host immune response and promoting viral replication. Despite the established endonuclease function of nsp15, little is known about other determinants of its cleavage specificity. In this study we investigate the role of RNA secondary structure in SARS-CoV-2 nsp15 endonuclease activity. Using a series of in vitro endonuclease assays, we observed that thermodynamically stable RNA structures were protected from nsp15 cleavage relative to RNAs lacking stable structure. We leveraged the s2m RNA from the SARS-CoV-1 3'UTR as a model for our structural studies as it adopts a well-defined structure with several uridines, two of which are unpaired and thus highly probable targets for nsp15 cleavage. We found that SARS-CoV-2 nsp15 specifically cleaves s2m at the unpaired uridine within the GNRNA pentaloop of the RNA. Further investigation revealed that the position of uridine within the pentaloop also impacted nsp15 cleavage efficiency suggesting that positioning within the pentaloop is necessary for optimal presentation of the scissile uridine and alignment within the nsp15 catalytic pocket. Our findings indicate that RNA secondary structure is an important determinant of nsp15 cleavage and provides insight into the molecular mechanisms of RNA recognition by nsp15.https://doi.org/10.1371/journal.pone.0290675
spellingShingle Indraneel Salukhe
Ryan Choi
Wesley Van Voorhis
Lynn Barrett
Jennifer Hyde
Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
PLoS ONE
title Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
title_full Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
title_fullStr Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
title_full_unstemmed Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
title_short Regulation of coronavirus nsp15 cleavage specificity by RNA structure.
title_sort regulation of coronavirus nsp15 cleavage specificity by rna structure
url https://doi.org/10.1371/journal.pone.0290675
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