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Figure 3
Local conformational differences between low-temperature and room-temperature (RT) structures of 3CLpro C2 polymorphs. Shown in the same orientation as in Fig. 1[link] are 25 multiconformer refinement molecular-dynamics (MD) traces of one protomer of each crystallographically symmetric dimer in the most frequent polymorph C2_a (PDB entry 6yb7, cryogenic temperature; PDB entry 6xb0, room temperature). The low-temperature model with PDB code 6yb7 has lower overall B factors (thinner trace bundles) and a corresponding higher resolution, but the MD traces show that local differences in conformational variability can be significant. The circled region at the top right of the molecule in the low-temperature model with PDB code 6yb7 exhibits flexibility similar to the cryogenic model with PDB code 7jkv shown in Fig. 1[link](b), while the RT model seems to be less variable in this region. In contrast, the helical region (bottom, red) seems to be less ordered in the RT model. At the same time, the overall low r.m.s.d.s between models remain comparable to the DPI estimates and do not inform about large local variances.

IUCrJ
Volume 8| Part 2| March 2021| Pages 238-256
ISSN: 2052-2525
https://doi.org/10.1107/S2052252521001159