COTRANSLATIONAL FOLDING OF PROTEINS

Many unfolded polypeptides are capable of refolding into their native structure upon the removal of the denaturant. However, the folding of the mature protein during renaturation does not accurately reflect the folding process of nascent proteins in the interior of the cell. This view resulted from the discovery of molecular chaperones known to mod ulate protein folding. Recent publications discussing the possible rol e and mechanisms of chaperone action suggest that folding in vivo may be a posttranslational process. Here we discuss data that indicate the final native structure and biological activity can be attainted by na scent protein on the ribosome, thus supporting the cotranslational fol ding hypothesis.