title: The charged linker of the molecular chaperone Hsp90 modulates domain contacts and biological function.
abstract: The heat shock protein 90 (Hsp90) is a dimeric molecular chaperone essential in numerous cellular processes. Its three domains (N, M, and C) are connected via linkers that allow the rearrangement of domains during Hsp90's chaperone cycle. A unique linker, called charged linker (CL), connects the N- and M-domain of Hsp90. We used an integrated approach, combining single-molecule techniques and biochemical and in vivo methods, to study the unresolved structure and function of this region. Here we show that the CL facilitates intramolecular rearrangements on the milliseconds timescale between a state in which the N-domain is docked to the M-domain and a state in which the N-domain is more flexible. The docked conformation is stabilized by 1.1 kBT (2.7 kJ/mol) through binding of the CL to the N-domain of Hsp90. Docking and undocking of the CL affects the much slower intermolecular domain movement and Hsp90's chaperone cycle governing client activation, cell viability, and stress tolerance.
authors.affiliation: Physik-Department E22 and.
authors.forename: Markus
authors.initials: M
authors.lastname: Jahn
authors.affiliation: Department Chemie, Technische Universität München, 85748 Munich, Germany; and.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rehn
authors.affiliation: Physik-Department E22 and.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Pelz
authors.affiliation: Physik-Department E22 and.
authors.forename: Björn
authors.initials: B
authors.lastname: Hellenkamp
authors.affiliation: Department Chemie, Technische Universität München, 85748 Munich, Germany; and Munich Center for Integrated Protein Science, 85748 Garching, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter
authors.affiliation: Physik-Department E22 and Munich Center for Integrated Protein Science, 85748 Garching, Germany thorsten.hugel@ph.tum.de mrief@ph.tum.de johannes.buchner@tum.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rief
authors.affiliation: Department Chemie, Technische Universität München, 85748 Munich, Germany; and Munich Center for Integrated Protein Science, 85748 Garching, Germany thorsten.hugel@ph.tum.de mrief@ph.tum.de johannes.buchner@tum.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Buchner
authors.affiliation: Physik-Department E22 and thorsten.hugel@ph.tum.de mrief@ph.tum.de johannes.buchner@tum.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Hugel
mesh_terms: D015153:Blotting, Western; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D015151:Immunoblotting; D008958:Models, Molecular; D052898:Optical Tweezers; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D014461:Ultracentrifugation
chemical_list: D003432:Cross-Linking Reagents; C074510:HSP82 protein, S cerevisiae; D018841:HSP90 Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins
keywords: FRET; Hsp90 conformation; asymmetric state; optical tweezers; single molecule