Introduction

Chaperonins are complex proteins which help proteins assume their correct conformation.
GroEL / ES
One of the best understood chaperonins is bacterial chaperonin called GroEL/ES complex. these protein as their name implies offer growth advantage to their cells as bacteria cells that has mutation in these protein often suffer growth difficulties. It is composed of two sub complex EL which is larger and ES which is smaller. It is suggested that thsese complexes uses the energy in phosphate bonds of ATP to correct protein structure.
Other resources
Molpaper has a great wallpaper on this protein (here)