6T3K:
reference: Visualizing group II intron dynamics between the first and second steps of splicing., Manigrasso J, Chillon I, Genna V, Vidossich P, Somarowthu S, Pyle AM, De Vivo M, Marcia M, Nat Commun. 2020 Jun 5;11(1):2837. doi: 10.1038/s41467-020-16741-4. PMID: 32503992

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).