6J6G:
reference: Structures of the Catalytically Activated Yeast Spliceosome Reveal the Mechanism of Branching., Wan R, Bai R, Yan C, Lei J, Shi Y, Cell. 2019 Apr 4;177(2):339-351.e13. doi: 10.1016/j.cell.2019.02.006. Epub 2019, Mar 14. PMID: 30879786

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