Conformational Ensembles from Experimental Data and Computer Simulations

Conformational Ensembles from Experimental Data

and Computer Simulations

Poster Abstracts

41-POS

Board 1

Dynamic Structure of the Protein Hsp90 Solved by a Hybrid Approach Based on Single

Molecule FRET

Thorsten Hugel

n/a, Freiburg, Germany.

Most molecular machines alternate dynamically between multiple conformations. Common

techniques are not ideal to study such conformational dynamics on relevant time scales from

micro-seconds to several seconds.

Here we present a hybrid approach based on single molecule FRET combined with X-ray crystal

structure data and simulations. This approach enables us to simultaneously access structure and

dynamics of a multi-domain protein in solution [1]. We applied this method to solve the dynamic

structures of the heat shock protein Hsp90 dimer in solution. The previously unknown open state

of yeast Hsp90 is represented by an ensemble of conformations with inter-domain fluctuations of

up to 25 Å.

In addition, we show how multicolor single molecule FRET allows us to identify microscopic

states in transient complexes. Conformational dynamics and nucleotide binding are

simultaneously detected for Hsp90. Their correlation is quantified using 3D ensemble hidden

Markov analysis, in and out of equilibrium [2,3].

[1] B. Hellenkamp, P. Wortmann, F. Kandzia, M. Zacharias, T. Hugel. Multidomain structure

and correlated dynamics determined by self-consistent FRET networks. Nat Meth;14(2):174-180

(2017).

[2] S. Schmid, M. Götz and T. Hugel. Single-Molecule Analysis beyond Dwell Times:

Demonstration and Assessment in and out of Equilibrium. Biophys J. 111:1375-1384 (2016)

[3] M. Götz, P. Wortmann, S. Schmid and T. Hugel. A multi-color single molecule FRET

approach to study protein dynamics and interactions simultaneously. Method Enzymol 581, 487-

516 (2016)