STRUCTURAL AND FUNCTIONAL STUDIES OF E COLI DNAJ

DESCRIPTION: The Hsp70 chaperone system of E. coli consists of the Hsp70 homologue DnaK, the Hsp40 homologue DnaJ, and the Hsp20 homologue GrpE. The coordinated action of these proteins is important in the folding of some proteins and in regulating the action of several macromolecular assemblies. This proposal focuses on the DnaJ component of this chaperone system. DnaJ is a co-chaperone that forms complexes with DnaK and also with substrate proteins. It contains four evolutionarily conserved, functionally distinct domains or modules. The structure of individual modules of DnaJ will be determined using 13C/15N/1H heteromuclear multidimensional NMR spectrosocpy, and residues that are important for function will be identified by site-directed mutagenesis. Complexes between modules of DnaJ and fragments or domains of its various protein partners will be characterized by NMR spectroscpy. These studies will provide insight into the roles of DnaJ and its homolgues in this important chaperone system.