creators_name: Kumar, Vignesh
creators_name: Peter, Joshua Jebakumar
creators_name: Sagar, Amin
creators_name: Ray, Arjun
creators_name: Jha, Mainak Pratim
creators_name: Rebeaud, Mathieu E
creators_name: Tiwari, Satyam
creators_name: Goloubinoff, Pierre
creators_name: Ashish, .
creators_name: Mapa, Koyeli
type: article
datestamp: 2019-12-05 15:11:55
lastmod: 2019-12-05 15:11:55
metadata_visibility: show
title: Inter-domain communication suppressing high intrinsic ATPase activity of Sse1 is essential for its co-dissaggregase activity with Ssa1.
ispublished: pub
subjects: QR
keywords: Hsp110; Hsp70; Molecular Dynamic simulation; Molecular chaperones; Small angle X-ray scattering; protein homeostasis; single-molecule FRET
note: Copyright of this article belongs to Wiley
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.
date: 2019-08-18
date_type: published
publication: The FEBS journal
publisher: Wiley
refereed: TRUE
issn: 1742-4658
official_url: https://febs.onlinelibrary.wiley.com/doi/full/10.1111/febs.15045
citation:   Kumar, Vignesh and Peter, Joshua Jebakumar and Sagar, Amin and Ray, Arjun and Jha, Mainak Pratim and Rebeaud, Mathieu E and Tiwari, Satyam and Goloubinoff, Pierre and Ashish, . and Mapa, Koyeli  (2019) Inter-domain communication suppressing high intrinsic ATPase activity of Sse1 is essential for its co-dissaggregase activity with Ssa1.  The FEBS journal.   ISSN 1742-4658