2.2 Å resolution cryo-EM structure of β-galactosidase in complex with a cell-permeant inhibitor.

Journal Article (Journal Article)

Cryo-electron microscopy (cryo-EM) is rapidly emerging as a powerful tool for protein structure determination at high resolution. Here we report the structure of a complex between Escherichia coli β-galactosidase and the cell-permeant inhibitor phenylethyl β-D-thiogalactopyranoside (PETG), determined by cryo-EM at an average resolution of ~2.2 angstroms (Å). Besides the PETG ligand, we identified densities in the map for ~800 water molecules and for magnesium and sodium ions. Although it is likely that continued advances in detector technology may further enhance resolution, our findings demonstrate that preparation of specimens of adequate quality and intrinsic protein flexibility, rather than imaging or image-processing technologies, now represent the major bottlenecks to routinely achieving resolutions close to 2 Å using single-particle cryo-EM.

Full Text

Duke Authors

Cited Authors

  • Bartesaghi, A; Merk, A; Banerjee, S; Matthies, D; Wu, X; Milne, JLS; Subramaniam, S

Published Date

  • June 2015

Published In

Volume / Issue

  • 348 / 6239

Start / End Page

  • 1147 - 1151

PubMed ID

  • 25953817

Pubmed Central ID

  • PMC6512338

Electronic International Standard Serial Number (EISSN)

  • 1095-9203

International Standard Serial Number (ISSN)

  • 0036-8075

Digital Object Identifier (DOI)

  • 10.1126/science.aab1576


  • eng