Heat shock protein 40: structural studies and their functional implications.

The mechanism by which Hsp40 and other molecular chaperones recognize and interact with non-native polypeptides is a fundamental question, as is how Hsp40 co-operates with Hsp70 to facilitate protein folding. Years of structural studies of Hsp40 from yeast and other species, conducted using X-ray protein crystallography, NMR and small-angle X-ray scattering, have shed light on the mechanisms how Hsp40 functions as a molecular chaperone and how Hsp40-Hsp70 pair promotes protein folding, protein transport and degradation. This review provides a discussion of recent structural studies of Hsp40s and their functional implications.