Intermolecular base stacking mediates RNA-RNA interaction in a crystal structure of the RNA chaperone Hfq

  • The RNA-chaperone Hfq catalyses the annealing of bacterial small RNAs (sRNAs) with target mRNAs to regulate gene expression in response to environmental stimuli. Hfq acts on a diverse set of sRNA-mRNA pairs using a variety of different molecular mechanisms. Here, we present an unusual crystal structure showing two Hfq-RNA complexes interacting via their bound RNA molecules. The structure contains two Hfq6:A18 RNA assemblies positioned face-to-face, with the RNA molecules turned towards each other and connected via interdigitating base stacking interactions at the center. Biochemical data further confirm the observed interaction, and indicate that RNA-mediated contacts occur between Hfq-RNA complexes with various (ARN)X motif containing RNA sequences in vitro, including the stress response regulator OxyS and its target, fhlA. A systematic computational survey also shows that phylogenetically conserved (ARN)X motifs are present in a subset of sRNAs, some of which share similar modular architectures. We hypothesise that Hfq can co-opt RNA-RNA base stacking, an unanticipated structural trick, to promote the interaction of (ARN)X motif containing sRNAs with target mRNAs on a "speed-dating" fashion, thereby supporting their regulatory function.

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Author:Eike C. Schulz, Markus Seiler, Cecilia Zuliani, Franka Voigt, Vladimir Rybin, Vivian Pogenberg, Norbert Mücke, Matthias Wilmanns, Toby J. Gibson, Orsolya Barabas
Pubmed Id:
Parent Title (English):Scientific reports
Publisher:Macmillan Publishers Limited, part of Springer Nature
Place of publication:[London]
Document Type:Article
Year of Completion:2017
Date of first Publication:2017/08/29
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2019/04/29
Tag:Gene regulation; Gene regulatory networks; Infection; Molecular biophysics; Small RNAs
Issue:1, Art. 9903
Page Number:15
First Page:1
Last Page:15
Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit
Institutes:Exzellenzcluster / Exzellenzcluster Makromolekulare Komplexe
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 4.0