6oay

Structure of the hyperactive ClpB mutant K476C, bound to casein, post-state

Loading... Status: waiting for Mol* initialization Structural highlights 6oay is a 7 chain structure with sequence from Bos taurus and Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.3Å Ligands: ADP, AGS Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Heat Shock Protein structures 3D structures of ClpB

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