Comparing Cryo-EM Reconstructions and Validating Atomic Model Fit Using Difference Maps

• DOI: 10.1021/acs.jcim.9b01103
• Publication Date: 2020-02-11T13:03:30Z
• Authors: Agnel Praveen Joseph; Ingvar Lagerstedt; Arjen Jakobi; Tom Burnley; Ardan Patwardhan; Maya Topf; Martyn Winn
• Keywords: Cryo-Electron Microscopy

Cryogenic electron microscopy (cryo-EM) is a powerful technique for determining structures of multiple conformational or compositional states macromolecular assemblies involved in cellular processes. Recent technological developments have led to leap the resolution many cryo-EM data sets, making atomic model building more common interpretation. We present method calculating differences between two maps map and fitted model. The proposed approach works by scaling using amplitude matching shells. To account variability local data, we include procedure that enables appropriate contrast. implemented as user-friendly tool CCP-EM software package. obtain clean interpretable differences, propose protocol involving steps process input output differences. demonstrate utility identifying including ligands. also highlight use difference evaluating fit maps.