4PKN:
reference: Formation and structures of GroEL:GroES2 chaperonin footballs, the protein-folding functional form., Fei X, Ye X, LaRonde NA, Lorimer GH, Proc Natl Acad Sci U S A. 2014 Aug 18. pii: 201412922. PMID: 25136110

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