Extended Data Fig. 5: Characterization of NMR-derived structural ensemble.

a) Results of cluster analysis after ab initio structure calculation without usage of RDCs. The 20 lowest energy structures (out of 200 calculated) were sorted according to their relative orientation of the Dz loop according to: Full winding around the RNA (cluster I), positioning downstream (cluster II) or upstream (cluster III) of the cleavage site, or other (cluster IV). Numbers below the structures refer to the number of structures in the respective fold. b) Same procedure as in a) but including RDC data. While cluster I is already the most populated in the absence of RDC restraints, it becomes by far the dominant fold after RDCs are included. In general, RDCs can be seen as one of the most reliable NMR-based probes of relative molecular orientation. As such, and albeit the remaining limitation in spectral quality and accuracy (Extended Data Fig. 4j, k), the observed effects on cluster selection appear significant. c) Overlay of the four lowest energy structures (out of 100) for each cluster (cluster I-III) after a more rigorous structural refinement and energy minimization.