Credit:
The regulatory particle (green) attempts to bind with the core particle (purple). If the core particle is not fully formed, bottom left, it tightly binds two chaperones to itself to deflect the regulatory particle’s attempts to bind and form a proteasome. If the core particle is more fully developed, bottom right, an affinity switch is triggered and the two chaperones are released to allow the regulatory particle to bind and form a proteasome.