ジャーナル: Structure / 年: 2018 タイトル: Atomic Resolution Cryo-EM Structure of β-Galactosidase. 著者: Alberto Bartesaghi / Cecilia Aguerrebere / Veronica Falconieri / Soojay Banerjee / Lesley A Earl / Xing Zhu / Nikolaus Grigorieff / Jacqueline L S Milne / Guillermo Sapiro / Xiongwu Wu / Sriram Subramaniam / 要旨: 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- ...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.