TY  - JOUR
A1  - Schubert, Jonathan
A1  - Schulze, Andrea
A1  - Prodromou, Chrisostomos
A1  - Neuweiler, Hannes
T1  - Two-colour single-molecule photoinduced electron transfer fluorescence imaging microscopy of chaperone dynamics
JF  - Nature Communications
N2  - Many proteins are molecular machines, whose function is dependent on multiple conformational changes that are initiated and tightly controlled through biochemical stimuli. Their mechanistic understanding calls for spectroscopy that can probe simultaneously such structural coordinates. Here we present two-colour fluorescence microscopy in combination with photoinduced electron transfer (PET) probes as a method that simultaneously detects two structural coordinates in single protein molecules, one colour per coordinate. This contrasts with the commonly applied resonance energy transfer (FRET) technique that requires two colours per coordinate. We demonstrate the technique by directly and simultaneously observing three critical structural changes within the Hsp90 molecular chaperone machinery. Our results reveal synchronicity of conformational motions at remote sites during ATPase-driven closure of the Hsp90 molecular clamp, providing evidence for a cooperativity mechanism in the chaperone’s catalytic cycle. Single-molecule PET fluorescence microscopy opens up avenues in the multi-dimensional exploration of protein dynamics and allosteric mechanisms.
KW  - chaperones
KW  - fluorescence spectroscopy
KW  - molecular conformation
KW  - single-molecule biophysics
KW  - total internal reflection microscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265754
VL  - 12
ER  - 
TY  - JOUR
A1  - Mercier, Rebecca
A1  - Wolmarans, Annemarie
A1  - Schubert, Jonathan
A1  - Neuweiler, Hannes
A1  - Johnson, Jill L.
A1  - LaPointe, Paul
T1  - The conserved NxNNWHW motif in Aha-type co-chaperones modulates the kinetics of Hsp90 ATPase stimulation
JF  - Nature Communications
N2  - Hsp90 is a dimeric molecular chaperone that is essential for the folding and activation of hundreds of client proteins. Co-chaperone proteins regulate the ATP-driven Hsp90 client activation cycle. Aha-type co-chaperones are the most potent stimulators of the Hsp90 ATPase activity but the relationship between ATPase regulation and in vivo activity is poorly understood. We report here that the most strongly conserved region of Aha-type co-chaperones, the N terminal NxNNWHW motif, modulates the apparent affinity of Hsp90 for nucleotide substrates. The ability of yeast Aha-type co-chaperones to act in vivo is ablated when the N terminal NxNNWHW motif is removed. This work suggests that nucleotide exchange during the Hsp90 functional cycle may be more important than rate of catalysis.
KW  - biophysics
KW  - cell growth
KW  - chaperones
KW  - enzymes
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224007
VL  - 10
ER  -