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Figure 6
Denoising high-frequency noise. The map of SARS-CoV-1 Spike Protein [EMD-34420 (Zhang et al., 2023BB50)] and its fragment focused on a single helix with the fitted atomistic model are presented. The map is part of the training set and has a resolution of 2.99 Å. The noisy map, constructed as a mean of two half-maps, is presented in (a). The final map published in the EMDB repository is shown in (b). The noisy sharpened mean map is presented in (c). The denoised and sharpened mean map is presented in (d). Contouring was tuned to make the maps most similar. The high-frequency structural features of the published and denoised maps are similar (see the α-helix); however, the denoised map provides a clear outlook of the overall architecture of the spike due to the removal of high-frequency noise.

IUCrJ
Volume 11| Part 5| September 2024| Pages 821-830
ISSN: 2052-2525
https://doi.org/10.1107/S2052252524005918