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Refined Cryo-EM Structure of the T4 Tail Tube: Exploring the Lowest Dose Limit.

ABSTRACT: The bacteriophage T4 contractile tail (containing a tube and sheath) was the first biological assembly reconstructed in three dimensions by electron microscopy at a resolution of ?35 Å in 1968. A single-particle reconstruction of the T4 baseplate was able to generate a 4.1 Å resolution map for the first two rings of the tube using the overall baseplate for alignment. We have now reconstructed the T4 tail tube at a resolution of 3.4 Å, more than a 1,000-fold increase in information content for the tube from 1968. We have used legacy software (Spider) to show that we can do better than the typical 2/3 Nyquist frequency. A reasonable map can be generated with only 1.5 electrons/Å2 using the higher dose images for alignment, but increasing the dose results in a better map, consistent with other reports that electron dose does not represent the main limitation on resolution in cryo-electron microscopy.

SUBMITTER: Zheng W

PROVIDER: S-EPMC5587399 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Refined Cryo-EM Structure of the T4 Tail Tube: Exploring the Lowest Dose Limit.

Zheng Weili W Wang Fengbin F Taylor Nicholas M I NMI Guerrero-Ferreira Ricardo C RC Leiman Petr G PG Egelman Edward H EH

Structure (London, England : 1993) 20170727 9

The bacteriophage T4 contractile tail (containing a tube and sheath) was the first biological assembly reconstructed in three dimensions by electron microscopy at a resolution of ∼35 Å in 1968. A single-particle reconstruction of the T4 baseplate was able to generate a 4.1 Å resolution map for the first two rings of the tube using the overall baseplate for alignment. We have now reconstructed the T4 tail tube at a resolution of 3.4 Å, more than a 1,000-fold increase in information content for th ...[more]

PMID: 28757144

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