Fig. 1
From: Retrieving high-resolution information from disordered 2D crystals by single-particle cryo-EM
Workflow employed to process 2D crystal data by single-particle analysis programs. Steps depicted within the dashed box were previously available in the 2D crystallography mode of FOCUS. A new GUI (Suppl. Fig. 1) was implemented to pick particles from the 2D crystals based on the unit cell positions obtained from classical unbending. Stacks of individual particles are then exported together with the associated metadata for processing with established SPA software. The particles extracted from the 2D crystal in each image are averaged in FOCUS for quality assessment, and rapid pre-refinement of the map is done with FREALIGN using these crystal averages as input. For simplicity, slices representing two crystal averages in different orientations are shown (light blue and light green). Then, the individual particles are initialized with the pre-refined alignment parameters and provided to FREALIGN to perform a full refinement to high resolution. These individual particles might end up having slightly different orientations than the crystal average, due to distortions in the 2D crystal lattice
