Atomic resolution cryo-EM structure of β-galactosidase

Publication Type

Journal Article

Year of Publication

2018

Journal

Structure

Volume

26

Pagination

848-856

Date Published

5/2018

Abstract

The advent of direct electron detectors has enabled the routine use of single-particle cryo-electron microscopy (EM) approaches to determine structures of a variety of protein complexes at near-atomic resolution. Here, we report the development of methods to account for local variations in defocus and beam-induced drift, and the implementation of a data-driven dose compensation scheme that significantly improves the extraction of high-resolution information recorded during exposure of the specimen to the electron beam. These advances enable determination of a cryo-EM density map for β-galactosidase bound to the inhibitor phenylethyl β-D-thiogalactopyranoside where the ordered regions are resolved at a level of detail seen in X-ray maps at ∼ 1.5 Å resolution. Using this density map in conjunction with constrained molecular dynamics simulations provides a measure of the local flexibility of the non-covalently bound inhibitor and offers further opportunities for structure-guided inhibitor design.

upload

Attachment Size
Bartesaghi_Structure2018.pdf 19.57 MB
Supplementary_movie.mp4 119.15 MB