Structural heterogeneity in microcrystalline ubiquitin studied by solid-state NMR.
Fasshuber, H.K., Lakomek, N.A., Habenstein, B., Loquet, A., Shi, C., Giller, K., Wolff, S., Becker, S., Lange, A.(2015) Protein Sci 24: 592-598
- PubMed: 25644665 
- DOI: https://doi.org/10.1002/pro.2654
- Primary Citation of Related Structures:  
2MSG - PubMed Abstract: 
By applying [1-(13) C]- and [2-(13) C]-glucose labeling schemes to the folded globular protein ubiquitin, a strong reduction of spectral crowding and increase in resolution in solid-state NMR (ssNMR) spectra could be achieved. This allowed spectral resonance assignment in a straightforward manner and the collection of a wealth of long-range distance information. A high precision solid-state NMR structure of microcrystalline ubiquitin was calculated with a backbone rmsd of 1.57 to the X-ray structure and 1.32 Å to the solution NMR structure. Interestingly, we can resolve structural heterogeneity as the presence of three slightly different conformations. Structural heterogeneity is most significant for the loop region β1-β2 but also for β-strands β1, β2, β3, and β5 as well as for the loop connecting α1 and β3. This structural polymorphism observed in the solid-state NMR spectra coincides with regions that showed dynamics in solution NMR experiments on different timescales.
Organizational Affiliation: 
Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany; Institut für Biologie, Humboldt-Universität, zu Berlin, Berlin, Germany.