Correction of preferred-orientation induced distortion in cryo-electron microscopy maps

Reconstruction maps of cryo-electron microscopy (cryo-EM) exhibit distortion when the cryo-EM dataset is incomplete, usually caused by unevenly distributed orientations. Prior efforts had been attempted to address this preferred orientation problem using tilt-collection strategy, modifications to grids or to air-water-interfaces. However, these approaches often require time-consuming experiments and the effect was always protein dependent. Here, we developed a procedure containing removing mis-aligned particles and an iterative reconstruction method based on signal-to-noise ratio of Fourier component to correct such distortion by recovering missing data using a purely computational algorithm. This procedure called Signal-to-Noise Ratio Iterative Reconstruction Method (SIRM) was applied on incomplete datasets of various proteins to fix distortion in cryo-EM maps and to a more isotropic resolution. In addition, SIRM provides a better reference map for further reconstruction refinements, r..., , , # SIRM: Open Source Data

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We have submitted the original chart files (.csv) and density maps (.mrc) related to the images in the article \"Correction of preferred-orientation induced distortion in cryo-electron microscopy maps\"

## Descriptions

### SIRM\_Fig1\_csv.rar

* *Fig1A.csv*: The CSV file corresponding to the histogram of Euler angle deviations in particle sets with different degrees of missing wedge under conventional refinement.
* *Fig1B.csv*: The CSV file corresponding to the histogram of Euler angle deviations in particle sets with different degrees of missing wedge After Cross-Validation process.

### SIRM\_Fig3\_MRC\_map.rar

* *groundTruth.mrc*: The ground-truth density map of Apo-ferritin without missing cone, corresponding to Fig.3A.
* *loss70_sameParticleNum.mrc*: The MC-35 density map of Apo-ferritin, corresponding to Fig.3D.
* *loss70_sameParticleNum_SIRM.mrc*: The MC-35 density map of Apo-ferritin after SIRM processing, corresponding to Fig.3G.
* *loss80_samePa...