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Figure 4
3D reconstructions of denoised T20S proteasome images. (a) Reconstruction of the original particle images without sharpening for the T20S proteasome in top (upper) and side (bottom) views. Iterative structure determination and refinement were performed using cryoSPARC (Punjani et al., 2017BB28) with D7 symmetry. For consistency with the other panels, the final reconstruction was calculated by transferring all parameters into RELION and using relion_reconstruct without symmetry (Zivanov et al., 2018BB42). (b) Reconstruction of denoised particle images in top (upper) and side (bottom) views, with the same orientation parameters as used in (a). (c) Reconstruction of the original particles after sharpening by −40 Å2. (d) Reconstruction of the denoised particles after sharpening by −180 Å2. (e) Comparison of rotational averages of the Fourier amplitude of reconstructions of original images (blue) and denoised images (red) calculated using the same parameter refined from the original images. (f) FSC curves between reconstructions of original and denoised particles using orientational parameters determined from the original particles (blue), between reconstructions of original and denoised particles using parameters determined from the denoised particles (orange) and between reconstructions of original particles using parameters determined from either the original or denoised particles (green). (g) Histogram of errors in the orientation parameters estimated during the refinement of denoised particles.

IUCrJ
Volume 7| Part 6| November 2020| Pages 1142-1150
ISSN: 2052-2525
https://doi.org/10.1107/S2052252520013184