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Progress and Potential of Electron Cryotomography as Illustrated by Its Application to Bacterial Chemoreceptor Arrays.
- Source :
-
Annual review of biophysics [Annu Rev Biophys] 2017 May 22; Vol. 46, pp. 1-21. Date of Electronic Publication: 2017 Feb 23. - Publication Year :
- 2017
-
Abstract
- Electron cryotomography (ECT) can produce three-dimensional images of biological samples such as intact cells in a near-native, frozen-hydrated state to macromolecular resolution (∼4 nm). Because one of its first and most common applications has been to bacterial chemoreceptor arrays, ECT's contributions to this field illustrate well its past, present, and future. While X-ray crystallography and nuclear magnetic resonance spectroscopy have revealed the structures of nearly all the individual components of chemoreceptor arrays, ECT has revealed the mesoscale information about how the components are arranged within cells. Receptors assemble into a universally conserved 12-nm hexagonal lattice linked by CheA/CheW rings. Membrane-bound arrays are single layered; cytoplasmic arrays are double layered. Images of in vitro reconstitutions have led to a model of how arrays assemble, and images of native arrays in different states have shown that the conformational changes associated with signal transduction are subtle, constraining models of activation and system cooperativity. Phase plates, better detectors, and more stable stages promise even higher resolution and broader application in the near future.
- Subjects :
- Bacterial Proteins chemistry
Bacterial Proteins genetics
Chemoreceptor Cells cytology
Chemoreceptor Cells ultrastructure
Cryoelectron Microscopy trends
Mutation
Protein Array Analysis
Protein Conformation
Signal Transduction
Bacterial Proteins metabolism
Chemoreceptor Cells metabolism
Cryoelectron Microscopy methods
Subjects
Details
- Language :
- English
- ISSN :
- 1936-1238
- Volume :
- 46
- Database :
- MEDLINE
- Journal :
- Annual review of biophysics
- Publication Type :
- Academic Journal
- Accession number :
- 28301773
- Full Text :
- https://doi.org/10.1146/annurev-biophys-070816-033555