1. Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic
2. Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, Trieste 34136, Italy
3. Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, Olomouc 771 46, Czech Republic
4. Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen 2200, Denmark
5. Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States