Protein translocation lumenal Hsp70 proteins

It is generally accepted that lumenal Hsp70 proteins bind to preproteins and assist in their translocation across membranes in a process requiring ATP hydrolysis. The mechanism of how Hsp70 exerts its action has been the subject of intense interest (Jensen andjohnson, 1999 Pilon and Schekman, 1999 Herrmann and Neupert, 2000 Matouschek et al.,... 

Fig. 3. Models of lumenal Hsp70 action in protein translocation. (I) In the Brownian ratchet model, the preprotein enters the lumen and associates with membrane-bound Hsp70. Hydrolysis of ATP results in the preprotein substrate being more tightly bound...

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