Molecular dynamics-based model refinement and validation for sub-5 Å cryo-electron microscopy maps
- University of Illinois at Urbana Champaign, United States
- University of Illinois at Urbana-Champaign, United States
- University of California, San Francisco, United States
Abstract
Two structure determination methods, based on the molecular dynamics flexible fitting (MDFF) paradigm, are presented that resolve sub-5-Å cryo-electron microscopy (EM) maps with either single structures or ensembles of such structures. The methods, denoted cascade MDFF and resolution exchange MDFF, sequentially re-refine a search model against a series of maps of progressively higher resolutions, which ends with the original experimental resolution. Application of sequential re-refinement enables MDFF to achieve a convergence radius of ~25Å demonstrated with the accurate modeling of β-galactosidase and TRPV1 proteins at 3.2Å and 3.4Å resolution. The MDFF refinements uniquely offer map-model validation and B-factor determination criteria based on the inherent dynamics of the respective macromolecules studied, captured employing local root mean square fluctuations. The MDFF tools are made available to researchers through an easy-to-use and cost-effective cloud computing resource on Amazon Web Services.
Data availability
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NIZN[FE4S4] AND NINI[FE4S4] CLUSTERS IN CLOSED AND OPEN ALPHA SUBUNITS OF ACETYL-COA SYNTHASE/CARBON MONOXIDE DEHYDROGENASEPublicly available at the Protien Data Bank (accession no. 1OAO).
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Structure of TRPV1 ion channel determined by single particle electron cryo-microscopyPublicly available at the Protien Data Bank (accession no. 3J5P).
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Structure of the capsaicin receptor, TRPV1, determined by single particle electron cryo-microscopyPublicly available at the EMDataBank (accesion no. EMD-5778).
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2.2 A resolution cryo-EM structure of beta-galactosidase in complex with a cell-permeant inhibitorPublicly available at the Protien Data Bank (accession no. 5A1A).
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2.2 A resolution cryo-EM structure of beta-galactosidase in complex with a cell-permeant inhibitorPublicly available at the EMDataBank (accesion no. EMD-2984).
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Cryo-EM structure of the human gamma-secretase complex at 3.4 angstrom resolution.Publicly available at the Protien Data Bank (accession no. 5A63).
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Cryo-EM structure of the human gamma-secretase complex at 3.4 angstrom resolutionPublicly available at the EMDataBank (accesion no. EMD-3061).
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Structure of a extracellular domainPublicly available at the Protien Data Bank (accession no. 4UPC).
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Three-dimensional structure of human gamma-secretase at 4.5 angstrom resolutionPublicly available at the EMDataBank (accesion no. EMD-2677).
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Thermoplasma acidophilum 20S proteasomePublicly available at the Protien Data Bank (accession no. 3J9I).
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3D reconstruction of archaeal 20S proteasomePublicly available at the EMDataBank (accesion no. EMD-5623).
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Structure of beta-galactosidase at 3.2-A resolution obtained by cryo-electron microscopyPublicly available at the Protien Data Bank (accession no. 3J7H).
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Structure of beta-galactosidase at 3.2-A resolution obtained by cryo-electron microscopyPublicly available at the EMDataBank (accesion no. EMD-5995).
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© 2016, singharoy et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Molecular dynamics-based model refinement and validation for sub-5 Å cryo-electron microscopy maps
eLife 5:e16105.
https://doi.org/10.7554/eLife.16105
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