Single-molecule Förster-resonance energy transfer (smFRET) experiments allow the study of biomolecular structure and dynamics in vitro and in vivo. We performed an international blind study involving 19 laboratories to assess the uncertainty of FRET experiments for proteins with respect to the measured FRET efficiency histograms, determination of distances, and the detection and quantification of structural dynamics. Using two protein systems with distinct conformational changes and dynamics, we obtained an uncertainty of the FRET efficiency ≤0.06, corresponding to an interdye distance precision of ≤2 Å and accuracy of ≤5 Å. We further discuss the limits for detecting fluctuations in this distance range and how to identify dye perturbations. Our work demonstrates the ability of smFRET experiments to simultaneously measure distances and avoid the averaging of conformational dynamics for realistic protein systems, highlighting its importance in the expanding toolbox of integrative structural biology.
FörderungenRoyal Society Biotechnology and Biological Sciences Research Council (BBSRC) Laender through the ONE MUNICH Project Munich Multiscale Biofabrication Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) LMUinnovative program BioImaging Network European Union Center for NanoScience DFG European Research Council (ERC) starting grant ERC Free State of Bavaria under the Excellence Strategy of the Federal Government Federal Ministry of Education and Research (BMBF) Nanosystems Initiative Munich Center for integrated protein science Munich Alexander von Humboldt postdoctoral fellowship German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) Marie Curie Actions (MSCA) ERC ADG MultiOrganelleDesign Agence Nationale pour la Recherche Hebrew University of Jerusalem Milner Fund National Institutes of Health Israel Science Foundation Wellcome Trust Royal Society Dorothy Hodgkin Research Fellowship Engineering and Physical Sciences Research Council (EPSRC) DFG under Germany's Excellence Strategy Research Foundation Flanders (FWO) US National Institutes of Health BMBF EPSRC Prize Fellowship