Inter-domain communication suppressing high intrinsic ATPase activity of Sse1 is essential for its co-dissaggregase activity with Ssa1.

Details

Serval ID
serval:BIB_FC40E12D6A97
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Inter-domain communication suppressing high intrinsic ATPase activity of Sse1 is essential for its co-dissaggregase activity with Ssa1.
Journal
The FEBS journal
Author(s)
Kumar V., Peter J.J., Sagar A., Ray A., Ashish A., Rebeaud M.E., Jha M.P., Tiwari S., Goloubinoff P., Mapa K.
ISSN
1742-4658 (Electronic)
ISSN-L
1742-464X
Publication state
Published
Issued date
17/02/2020
Peer-reviewed
Oui
Language
english
Notes
Publication types: Journal Article
Publication Status: aheadofprint
Abstract
In eukaryotes, Hsp110s are unambiguous cognates of the Hsp70 chaperones, in primary sequence, domain organization and structure. Hsp110s function as nucleotide exchange factors (NEFs) for the Hsp70s although their apparent loss of Hsp70-like chaperone activity, nature of inter-domain communication and breadth of domain functions, are still puzzling. Here, by combining single molecule FRET, small angle X-ray scattering measurements (SAXS) and MD simulation, we show that yeast Hsp110, Sse1 lacks canonical Hsp70-like inter-domain allostery. However, the protein exhibits unique non-canonical conformational changes within its domains. Sse1 maintains an open-lid substrate-binding domain (SBD) in close contact with its nucleotide-binding domain (NBD), irrespective of its ATP hydrolysis status. To further appreciate such ATP-hydrolysis independent exhaustive interaction between two domains of Hsp110s, NBD-SBD chimera were constructed between Hsp110 (Sse1) and Hsp70 (Ssa1). In Sse1/Ssa1 chimera, we observed undocking of two domains leading to complete loss of NEF activity of Sse1. Interestingly, chimeric proteins exhibited significantly enhanced ATPase rate of Sse1-NBD compared to wild type protein, implying that intrinsic ATPase activity of the protein remains mostly repressed. Apart from repressing the high ATPase activity of its NBD, interactions between two domains confer thermal stability to Sse1 and play critical role in the (co)chaperoning function of Sse1 in Ssa1-mediated disaggregation activity. Altogether, Sse1 exhibits a unique inter-domain interaction, which is essential for its NEF activity, suppression of high intrinsic ATPase activity, co-chaperoning activity in disaggregase machinery and stability of the protein.
Keywords
Hsp110, Hsp70, Molecular Dynamic simulation, Molecular chaperones, Small angle X-ray scattering, protein homeostasis, single-molecule FRET
Pubmed
Create date
31/08/2019 0:11
Last modification date
15/07/2020 6:26
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