6Z3R:
reference: Structure of substrate-bound SMG1-8-9 kinase complex reveals molecular basis for phosphorylation specificity., Langer LM, Gat Y, Bonneau F, Conti E, Elife. 2020 May 29;9. pii: 57127. doi: 10.7554/eLife.57127. PMID: 32469312

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