Multidomain proteins: conformational dynamics and folding

  PGK labelpositions Fitter Illustration of the PGK structure highlighting several label positions

Large scale motions of globular domains are often crucial for the activity of multidomain proteins. We have employed single molecule Förster resonance energy transfer (smFRET) for the characterization of large scale domain motions in the case of Phosphoglycerate kinase (PGK). PGK is a key enzyme in glycolysis which has a widely open domain structure with a hinge near the active centre between the two domains.

In prokaryotic and even more in eukaryotic cells the predominant fraction of the whole proteome belongs to the class of multidomain protein. However, because of methodical reasons our existing knowledge about mechanisms and principles of protein folding results mainly from studies on smaller singledomain proteins. Therefore we investigated folding of PGK by single molecule FRET with dyes attached in the N- and C-domains. In addition to inter-domain distances we currently map several intra-domain distances for different folding states. This will provide us with a more complete picture about the sequential order of folding/unfolding transitions of individual domains.



M. Gabba, S. Poblete, T. Rosenkranz, A. Katranidis, D. Kempe, T. Züchner, R.G. Winkler, G. Gompper, and J. Fitter
Conformational State Distribution and Catalytically Relevant Dynamics of a Hinge-Bending Enzyme Studied by Single-Molecule FRET and a Coarse-Grained Simulation .
Biophys. J., 107, 1913-1923, (2014)

T. Rosenkranz, R. Schlesinger, M. Gabba, J. Fitter
Native and unfolded states of a phosphoglycerate kinase studied by single molecule FRET .
ChemPhysChem, 12, 704-710, (2011)