Analysis of Global and Site-Specific Radiation Damage in Cryo-EM.
Structure
; 26(5): 759-766.e4, 2018 05 01.
Article
em En
| MEDLINE
| ID: mdl-29706530
ABSTRACT
Micro-crystal electron diffraction (MicroED) combines the efficiency of electron scattering with diffraction to allow structure determination from nano-sized crystalline samples in cryoelectron microscopy (cryo-EM). It has been used to solve structures of a diverse set of biomolecules and materials, in some cases to sub-atomic resolution. However, little is known about the damaging effects of the electron beam on samples during such measurements. We assess global and site-specific damage from electron radiation on nanocrystals of proteinase K and of a prion hepta-peptide and find that the dynamics of electron-induced damage follow well-established trends observed in X-ray crystallography. Metal ions are perturbed, disulfide bonds are broken, and acidic side chains are decarboxylated while the diffracted intensities decay exponentially with increasing exposure. A better understanding of radiation damage in MicroED improves our assessment and processing of all types of cryo-EM data.
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MEDLINE
Assunto principal:
Microscopia Crioeletrônica
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article