On the damage done to the structure of the Thermoplasma acidophilum proteasome by electron radiation.

ABSTRACT: It has long been known that proteins are damaged when they are exposed to the electron beam in an electron microscope. Here we show that exposure to electrons under cryo-EM conditions leads to a small change in the quaternary structure of the Thermoplasma acidophilum proteasome, and that backbones atoms belonging to the α-helices in this molecule appear to be particular prone to chemical damage. A chemical mechanism is proposed for this damage. Both this local chemical effect and the more global quaternary structure effect appear to heterogenize samples leading to a radiation dose-dependent degradation of the resolution of the EM maps obtained from this molecule.

SUBMITTER: Wang J 

PROVIDER: S-EPMC6237698 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature