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Schlagwörter:
13C sparse labeling; dynamics; heterogeneity; solid-state NMR; ubiquitin
Zusammenfassung:
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 regions 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. This article is protected by copyright. All rights reserved.
