1. Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
2. David Van Andel Advanced Cryo-Electron Microscopy Suite, Van Andel Research Institute, Grand Rapids, Michigan 49503, United States
3. COMSOL, Inc., Burlington, Massachusetts 01803, United States
4. Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, U.K.
5. Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
6. Michigan Institute for Translational Nanotechnology, Ypsilanti, Michigan 48198, United States