Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study

In the Avocado Sunblotch Viroid (ASBVd: 249-nt) from the Avsunviroidae family, a symmetric rolling-circle replication operates through an autocatalytic mechanism mediated by hammerhead ribozymes (HHR) embedded in both polarity strands. The concatenated multimeric ASBVd (+) and ASBVd (−) RNAs thus ge...

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Main Authors:	Leclerc, Fabrice, Zaccai, Giuseppe, Vergne, Jacques, Řìhovà, Martina, Martel, Anne, Maurel, Marie-Christine
Format:	Online
Language:	English
Published:	Nature Publishing Group 2016
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4960562/

id	pubmed-4960562
recordtype	oai_dc
spelling	pubmed-49605622016-08-05 Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study Leclerc, Fabrice Zaccai, Giuseppe Vergne, Jacques Řìhovà, Martina Martel, Anne Maurel, Marie-Christine Article In the Avocado Sunblotch Viroid (ASBVd: 249-nt) from the Avsunviroidae family, a symmetric rolling-circle replication operates through an autocatalytic mechanism mediated by hammerhead ribozymes (HHR) embedded in both polarity strands. The concatenated multimeric ASBVd (+) and ASBVd (−) RNAs thus generated are processed by cleavage to unit-length where ASBVd (−) self-cleaves with more efficiency. Absolute scale small angle neutron scattering (SANS) revealed a temperature-dependent dimer association in both ASBVd (−) and its derived 79-nt HHR (−). A joint thermodynamic analysis of SANS and catalytic data indicates the rate-determining step corresponds to the dimer/monomer transition. 2D and 3D models of monomeric and dimeric HHR (−) suggest that the inter-molecular contacts stabilizing the dimer (between HI and HII domains) compete with the intra-molecular ones stabilizing the active conformation of the full-length HHR required for an efficient self-cleavage. Similar competing intra- and inter-molecular contacts are proposed in ASBVd (−) though with a remoter region from an extension of the HI domain. Nature Publishing Group 2016-07-26 /pmc/articles/PMC4960562/ /pubmed/27456224 http://dx.doi.org/10.1038/srep30287 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Leclerc, Fabrice Zaccai, Giuseppe Vergne, Jacques Řìhovà, Martina Martel, Anne Maurel, Marie-Christine
spellingShingle	Leclerc, Fabrice Zaccai, Giuseppe Vergne, Jacques Řìhovà, Martina Martel, Anne Maurel, Marie-Christine Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
author_facet	Leclerc, Fabrice Zaccai, Giuseppe Vergne, Jacques Řìhovà, Martina Martel, Anne Maurel, Marie-Christine
author_sort	Leclerc, Fabrice
title	Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
title_short	Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
title_full	Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
title_fullStr	Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
title_full_unstemmed	Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study
title_sort	self-assembly controls self-cleavage of hhr from asbvd (−): a combined sans and modeling study
description	In the Avocado Sunblotch Viroid (ASBVd: 249-nt) from the Avsunviroidae family, a symmetric rolling-circle replication operates through an autocatalytic mechanism mediated by hammerhead ribozymes (HHR) embedded in both polarity strands. The concatenated multimeric ASBVd (+) and ASBVd (−) RNAs thus generated are processed by cleavage to unit-length where ASBVd (−) self-cleaves with more efficiency. Absolute scale small angle neutron scattering (SANS) revealed a temperature-dependent dimer association in both ASBVd (−) and its derived 79-nt HHR (−). A joint thermodynamic analysis of SANS and catalytic data indicates the rate-determining step corresponds to the dimer/monomer transition. 2D and 3D models of monomeric and dimeric HHR (−) suggest that the inter-molecular contacts stabilizing the dimer (between HI and HII domains) compete with the intra-molecular ones stabilizing the active conformation of the full-length HHR required for an efficient self-cleavage. Similar competing intra- and inter-molecular contacts are proposed in ASBVd (−) though with a remoter region from an extension of the HI domain.
publisher	Nature Publishing Group
publishDate	2016
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4960562/
_version_	1613614879556501504

Self-assembly Controls Self-cleavage of HHR from ASBVd (−): a Combined SANS and Modeling Study

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