Acknowledgements

This work was funded by the National Aeronautics and Space Administration grant 80NSSC18K1139 awarded to LDW and ASP. We would like to thank the following collaborators, whose input has been invaluable to our work:

• Prof. Khanh Dao Duc & Mr. Artem Kushner at University of British Columbia (https://kdaoduc.com/)
• Dr. Blake Sweeney (RNAcentral)
• Dr. Anton I. Petrov (R2DT)
• Dr. Chad R. Bernier (RiboVision)
• Dr. Alexander Rose, (Mol*)
• Prof. Craig Zirbel (RNA3Dhub)

Our webserver would not be possible without these free resources:

• Sequences and taxonomies were retrieved from the National Center for Biotechnology Information, UniProt, and RNAcentral;
• PDB identifiers are filtered through the API provided by Dr. Khanh Dao Duc and Mr. Artem Kushner through their project for ribosomal structure analysis;
• RNA secondary structure diagrams - R2DT (https://doi.org/10.1038/s41467-021-23555-5);
• Alignment viewer – modified version of the react implementation for the MSAViewer (10.1093/bioinformatics/btw474);
• RNA Topology Viewer – modified version of the PDBe RNA viewer;
• FR3D - the 3D derived base pairs annotated according to Leontis and Westhof's notation (http://rna.bgsu.edu/rna3dhub/pdb/7K00/interactions/fr3d/basepairs);
• PDB topologies provided through the EBI PDBe REST API;
• MolStar Viewer – viewer ; Github;
• Parsing of sequences and alignments and calculation of frequencies was possible thanks to the Biopython package;
• Sequence-alignment mapping is handled by MAFFT.