FIGURE 1.

Cellular functions of chaperones in the context of a protein folding landscape. The protein polypeptide chain is shown yellow, with different secondary structure elements highlighted in purple and blue. The protein navigates a rugged free energy surface. The native conformation is one out of several local minima, representing different conformational states that are shown below the surface. Chaperones participate in a broad range of cellular processes which define a range of functions listed in italics. These navigate the protein along the energy landscape. Blue arrows indicate transitions that chaperones facilitate, whereas black arrows with red inversed T indicate transitions chaperones prevent. Figure modified from Jahn and Radford (2005).