Group II chaperonins are present in eukaryotes and archaea and are essential mediators of cellular protein folding. This process is critically dependent on the closure of a built-in lid, which is triggered by ATP hydrolysis, but the structural rearrangements and molecular events leading to lid closure are unknown. Using cryo-electron microscopy, the structures of an archaeal group II chaperonin in the open and closed states are now reported, providing details of this mechanism.
- Junjie Zhang
- Matthew L. Baker
- Wah Chiu
