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Electron Crystallography (electron + crystallography)

Distribution by Scientific Domains
Chemistry66%

Selected Abstracts

Gjønnes Medal in Electron Crystallography , call for nominations

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2009
DOI: 10.1107/S010876730904244
First page of article [source]

Electron crystallography of aquaporins

IUBMB LIFE, Issue 7 2008
Simeon Andrews
Abstract Aquaporins are a family of ubiquitous membrane proteins that form a pore for the permeation of water. Both electron and X-ray crystallography played major roles in determining the atomic structures of a number of aquaporins. This review focuses on electron crystallography, and its contribution to the field of aquaporin biology. We briefly discuss electron crystallography and the two-dimensional crystallization process. We describe features of aquaporins common to both electron and X-ray crystallographic structures; as well as some structural insights unique to electron crystallography, including aquaporin junction formation and lipid-protein interactions. © 2008 IUBMB IUBMB Life, 60(7): 430,436, 2008 [source]

Determination of lattice-transform density profiles for multilayered three-dimensional microcrystals in electron crystallography

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000
Eva Dimmeler
Electron crystallography on multilayered three-dimensional microcrystals has been limited in application by the need to define precisely the three-dimensional shape of the diffraction density profiles. A new method is presented here to obtain this profile from experimental spot positions which are shifted in a characteristic way from the expected Bragg positions. While the Bragg positions are defined by the diffraction geometry, the characteristic shift additionally depends on the density profile in Fourier space. In general, these two effects are intermingled. A new correlation approach is presented which uses characteristic shift patterns to separate these effects. This technique also allows the determination of all three crystallographic unit-cell dimensions from a single tilted electron diffraction pattern. It was tested on simulated diffraction patterns and applied to experimental data of frozen hydrated crystals of the protein catalase. Since multilayered catalase crystals with different numbers of crystallographic layers were studied, an inhomogeneous data set had to be evaluated. Processing of such data is now possible using the new correlation approach. [source]

Electron crystallography of aquaporins

IUBMB LIFE, Issue 7 2008
Simeon Andrews
Abstract Aquaporins are a family of ubiquitous membrane proteins that form a pore for the permeation of water. Both electron and X-ray crystallography played major roles in determining the atomic structures of a number of aquaporins. This review focuses on electron crystallography, and its contribution to the field of aquaporin biology. We briefly discuss electron crystallography and the two-dimensional crystallization process. We describe features of aquaporins common to both electron and X-ray crystallographic structures; as well as some structural insights unique to electron crystallography, including aquaporin junction formation and lipid-protein interactions. © 2008 IUBMB IUBMB Life, 60(7): 430,436, 2008 [source]

Determination of lattice-transform density profiles for multilayered three-dimensional microcrystals in electron crystallography

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000
Eva Dimmeler
Electron crystallography on multilayered three-dimensional microcrystals has been limited in application by the need to define precisely the three-dimensional shape of the diffraction density profiles. A new method is presented here to obtain this profile from experimental spot positions which are shifted in a characteristic way from the expected Bragg positions. While the Bragg positions are defined by the diffraction geometry, the characteristic shift additionally depends on the density profile in Fourier space. In general, these two effects are intermingled. A new correlation approach is presented which uses characteristic shift patterns to separate these effects. This technique also allows the determination of all three crystallographic unit-cell dimensions from a single tilted electron diffraction pattern. It was tested on simulated diffraction patterns and applied to experimental data of frozen hydrated crystals of the protein catalase. Since multilayered catalase crystals with different numbers of crystallographic layers were studied, an inhomogeneous data set had to be evaluated. Processing of such data is now possible using the new correlation approach. [source]

Quasi-dynamical electron diffraction , a kinematic type of expression for the dynamical diffracted-beam amplitudes

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2000
Lian-Mao Peng
It is shown that to a good approximation the dynamical diffracted electron-beam amplitudes may be expressed in a form that is identical to that of the kinematic theory of electron diffraction. The validity of this approximate form of the dynamical electron diffraction is illustrated for thin films of GaAs and Au crystals, and its implications in electron crystallography for structural determination and refinement are discussed. [source]