TY - JOUR
T1 - The ATP hydrolysis-dependent reaction cycle of the Escherichia coli Hsp70 system - DnaK, DnaJ, and GrpE
AU - Szabo, Alexander
AU - Langer, Thomas
AU - Schröder, Hartwig
AU - Flanagan, John
AU - Bukau, Bernd
AU - Hartl, F. Ulrich
PY - 1994/10/25
Y1 - 1994/10/25
N2 - Molecular chaperones of the Hsp70 class bind unfolded polypeptide chains and are thought to be involved in the cellular folding pathway of many proteins. DnaK, the Hsp70 protein of Escherichia coli, is regulated by the chaperone protein DnaJ and the cofactor GrpE. To gain a biologically relevant understanding of the mechanism of Hsp70 action, we have analyzed a model reaction in which DnaK, DnaJ, and GrpE mediate the folding of denatured firefly luciferase. The binding and release of substrate protein for folding involves the following ATP hydrolysis-dependent cycle: (i) unfolded luciferase binds initially to DnaJ; (ii) upon interaction with luciferase- DnaJ, DnaK hydrolyzes its bound ATP, resulting in the formation of a stable luciferase-DnaK-DnaJ complex; (iii) GrpE releases ADP from DnaK; and (iv) ATP binding to DnaK triggers the release of substrate protein, thus completing the reaction cycle. A single cycle of binding and release leads to folding of only a fraction of luciferase molecules. Several rounds of ATP-dependent interaction with DnaK and DnaJ are required for fully efficient folding.
AB - Molecular chaperones of the Hsp70 class bind unfolded polypeptide chains and are thought to be involved in the cellular folding pathway of many proteins. DnaK, the Hsp70 protein of Escherichia coli, is regulated by the chaperone protein DnaJ and the cofactor GrpE. To gain a biologically relevant understanding of the mechanism of Hsp70 action, we have analyzed a model reaction in which DnaK, DnaJ, and GrpE mediate the folding of denatured firefly luciferase. The binding and release of substrate protein for folding involves the following ATP hydrolysis-dependent cycle: (i) unfolded luciferase binds initially to DnaJ; (ii) upon interaction with luciferase- DnaJ, DnaK hydrolyzes its bound ATP, resulting in the formation of a stable luciferase-DnaK-DnaJ complex; (iii) GrpE releases ADP from DnaK; and (iv) ATP binding to DnaK triggers the release of substrate protein, thus completing the reaction cycle. A single cycle of binding and release leads to folding of only a fraction of luciferase molecules. Several rounds of ATP-dependent interaction with DnaK and DnaJ are required for fully efficient folding.
UR - http://www.scopus.com/inward/record.url?scp=0028151509&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028151509&partnerID=8YFLogxK
U2 - 10.1073/pnas.91.22.10345
DO - 10.1073/pnas.91.22.10345
M3 - Article
C2 - 7937953
AN - SCOPUS:0028151509
SN - 0027-8424
VL - 91
SP - 10345
EP - 10349
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 22
ER -