5TKY

Crystal structure of the co-translational Hsp70 chaperone Ssb in the ATP-bound, open conformation

Summary for 5TKY

• Entry DOI: 10.2210/pdb5tky/pdb
• Descriptor: Putative uncharacterized protein, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: hsp70, chaperone, ribosome, translation
• Biological source: Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719)
• Total number of polymer chains: 2
• Total formula weight: 136920.97

Authors

Gumiero, A.,Gese, G.V.,Weyer, F.A.,Lapouge, K.,Sinning, I. (deposition date: 2016-10-10, release date: 2016-11-16, Last modification date: 2024-11-13)

Primary citation

Gumiero, A.,Conz, C.,Gese, G.V.,Zhang, Y.,Weyer, F.A.,Lapouge, K.,Kappes, J.,von Plehwe, U.,Schermann, G.,Fitzke, E.,Wolfle, T.,Fischer, T.,Rospert, S.,Sinning, I.
Interaction of the cotranslational Hsp70 Ssb with ribosomal proteins and rRNA depends on its lid domain.
Nat Commun, 7:13563-13563, 2016

PubMed Abstract: Cotranslational chaperones assist in de novo folding of nascent polypeptides in all organisms. In yeast, the heterodimeric ribosome-associated complex (RAC) forms a unique chaperone triad with the Hsp70 homologue Ssb. We report the X-ray structure of full length Ssb in the ATP-bound open conformation at 2.6 Å resolution and identify a positively charged region in the α-helical lid domain (SBDα), which is present in all members of the Ssb-subfamily of Hsp70s. Mutational analysis demonstrates that this region is strictly required for ribosome binding. Crosslinking shows that Ssb binds close to the tunnel exit via contacts with both, ribosomal proteins and rRNA, and that specific contacts can be correlated with switching between the open (ATP-bound) and closed (ADP-bound) conformation. Taken together, our data reveal how Ssb dynamics on the ribosome allows for the efficient interaction with nascent chains upon RAC-mediated activation of ATP hydrolysis.

PubMed: 27882919
DOI: 10.1038/ncomms13563

Experimental method

X-RAY DIFFRACTION (2.6 Å)