Structural highlights
Function
CLPB_ECOLI Part of a stress-induced multi-chaperone system, it is involved in the recovery of the cell from heat-induced damage, in cooperation with DnaK, DnaJ and GrpE. Acts before DnaK, in the processing of protein aggregates. Protein binding stimulates the ATPase activity; ATP hydrolysis unfolds the denatured protein aggregates, which probably helps expose new hydrophobic binding sites on the surface of ClpB-bound aggregates, contributing to the solubilization and refolding of denatured protein aggregates by DnaK.[1] [2] [3]
Publication Abstract from PubMed
Bacterial ClpB and yeast Hsp104 are homologous Hsp100 protein disaggregases that serve critical functions in proteostasis by solubilizing protein aggregates. Two AAA+ nucleotide binding domains (NBDs) power polypeptide translocation through a central channel comprised of a hexameric spiral of protomers that contact substrate via conserved pore-loop interactions. Here we report cryo-EM structures of a hyperactive ClpB variant bound to the model substrate, casein in the presence of slowly hydrolysable ATPgammaS, which reveal the translocation mechanism. Distinct substrate-gripping interactions are identified for NBD1 and NBD2 pore loops. A trimer of N-terminal domains define a channel entrance that binds the polypeptide substrate adjacent to the topmost NBD1 contact. NBD conformations at the seam interface reveal how ATP hydrolysis-driven substrate disengagement and re-binding are precisely tuned to drive a directional, stepwise translocation cycle.
Structural basis for substrate gripping and translocation by the ClpB AAA+ disaggregase.,Rizo AN, Lin J, Gates SN, Tse E, Bart SM, Castellano LM, DiMaio F, Shorter J, Southworth DR Nat Commun. 2019 Jun 3;10(1):2393. doi: 10.1038/s41467-019-10150-y. PMID:31160557[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Barnett ME, Zolkiewska A, Zolkiewski M. Structure and activity of ClpB from Escherichia coli. Role of the amino-and -carboxyl-terminal domains. J Biol Chem. 2000 Dec 1;275(48):37565-71. PMID:10982797 doi:http://dx.doi.org/10.1074/jbc.M005211200
- ↑ Mogk A, Schlieker C, Strub C, Rist W, Weibezahn J, Bukau B. Roles of individual domains and conserved motifs of the AAA+ chaperone ClpB in oligomerization, ATP hydrolysis, and chaperone activity. J Biol Chem. 2003 May 16;278(20):17615-24. Epub 2003 Mar 6. PMID:12624113 doi:http://dx.doi.org/10.1074/jbc.M209686200
- ↑ Kedzierska S, Akoev V, Barnett ME, Zolkiewski M. Structure and function of the middle domain of ClpB from Escherichia coli. Biochemistry. 2003 Dec 9;42(48):14242-8. PMID:14640692 doi:http://dx.doi.org/10.1021/bi035573d
- ↑ Rizo AN, Lin J, Gates SN, Tse E, Bart SM, Castellano LM, DiMaio F, Shorter J, Southworth DR. Structural basis for substrate gripping and translocation by the ClpB AAA+ disaggregase. Nat Commun. 2019 Jun 3;10(1):2393. doi: 10.1038/s41467-019-10150-y. PMID:31160557 doi:http://dx.doi.org/10.1038/s41467-019-10150-y
