The emergence of the chaperone machines.

To ensure proper polypeptide folding, oligomerization and transport, elaborate molecular 'chaperone machines' have evolved. These machines are usually composed of a major chaperone protein that binds promiscuously to nascent, unfolded, misfolded or aggregated polypeptides and a set of chaperone 'cohorts', whose function is to enhance efficiency and ensure recycling. These chaperone machines can function by themselves or synergistically to carry out their various tasks.