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Structural basis for ligand binding to the guanidine-II riboswitch

The guanidine-II riboswitch, also known as mini-ykkC, is a conserved mRNA element with more than 800 examples in bacteria. It consists of two stem–loops capped by identical, conserved tetraloops that are separated by a linker region of variable length and sequence. Like the guanidine-I riboswitch, i...

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Detalles Bibliográficos
Autores principales: Reiss, Caroline W., Strobel, Scott A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cold Spring Harbor Laboratory Press 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5558903/
https://www.ncbi.nlm.nih.gov/pubmed/28600356
http://dx.doi.org/10.1261/rna.061804.117
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author Reiss, Caroline W.
Strobel, Scott A.
author_facet Reiss, Caroline W.
Strobel, Scott A.
author_sort Reiss, Caroline W.
collection PubMed
description The guanidine-II riboswitch, also known as mini-ykkC, is a conserved mRNA element with more than 800 examples in bacteria. It consists of two stem–loops capped by identical, conserved tetraloops that are separated by a linker region of variable length and sequence. Like the guanidine-I riboswitch, it controls the expression of guanidine carboxylases and SugE-like genes. The guanidine-II riboswitch specifically binds free guanidinium cations and functions as a translationally controlled on-switch. Here we report the structure of a P2 stem–loop from the Pseudomonas aeruginosa guanidine-II riboswitch aptamer bound to guanidine at 1.57 Å resolution. The hairpins dimerize via the conserved tetraloop, which also contains the binding pocket. Two guanidinium molecules bind near the dimerization interface, one in each tetraloop. The guanidinium cation is engaged in extensive hydrogen bonding to the RNA. Contacts include the Hoogsteen face of a guanine base and three nonbridging phosphate oxygens. Cation–π interactions and ionic interactions also stabilize ligand binding. The guanidine-II riboswitch utilizes the same recognition strategies as the guanidine-I riboswitch while adopting an entirely different and much smaller RNA fold.
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spelling pubmed-55589032018-09-01 Structural basis for ligand binding to the guanidine-II riboswitch Reiss, Caroline W. Strobel, Scott A. RNA Report The guanidine-II riboswitch, also known as mini-ykkC, is a conserved mRNA element with more than 800 examples in bacteria. It consists of two stem–loops capped by identical, conserved tetraloops that are separated by a linker region of variable length and sequence. Like the guanidine-I riboswitch, it controls the expression of guanidine carboxylases and SugE-like genes. The guanidine-II riboswitch specifically binds free guanidinium cations and functions as a translationally controlled on-switch. Here we report the structure of a P2 stem–loop from the Pseudomonas aeruginosa guanidine-II riboswitch aptamer bound to guanidine at 1.57 Å resolution. The hairpins dimerize via the conserved tetraloop, which also contains the binding pocket. Two guanidinium molecules bind near the dimerization interface, one in each tetraloop. The guanidinium cation is engaged in extensive hydrogen bonding to the RNA. Contacts include the Hoogsteen face of a guanine base and three nonbridging phosphate oxygens. Cation–π interactions and ionic interactions also stabilize ligand binding. The guanidine-II riboswitch utilizes the same recognition strategies as the guanidine-I riboswitch while adopting an entirely different and much smaller RNA fold. Cold Spring Harbor Laboratory Press 2017-09 /pmc/articles/PMC5558903/ /pubmed/28600356 http://dx.doi.org/10.1261/rna.061804.117 Text en © 2017 Reiss and Strobel; Published by Cold Spring Harbor Laboratory Press for the RNA Society http://creativecommons.org/licenses/by-nc/4.0/ This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http://rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
spellingShingle Report
Reiss, Caroline W.
Strobel, Scott A.
Structural basis for ligand binding to the guanidine-II riboswitch
title Structural basis for ligand binding to the guanidine-II riboswitch
title_full Structural basis for ligand binding to the guanidine-II riboswitch
title_fullStr Structural basis for ligand binding to the guanidine-II riboswitch
title_full_unstemmed Structural basis for ligand binding to the guanidine-II riboswitch
title_short Structural basis for ligand binding to the guanidine-II riboswitch
title_sort structural basis for ligand binding to the guanidine-ii riboswitch
topic Report
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5558903/
https://www.ncbi.nlm.nih.gov/pubmed/28600356
http://dx.doi.org/10.1261/rna.061804.117
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