Joachim Frank. Three-Dimensional Electron Microscopy of Macromolecular Assemblies. Academic Press, 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... for example, algorithms for particle selection in two dimensions are crucial to determining the three dimensional reconstruction of electron microscopy images [48] This problem was first studied by [45] and has subsequently been studied by many researchers(see, e.g. 12, 17, 29, 37, 41, 44] and [11] for further references) Typical approaches to this problem make use of heuristics, although there are also approaches that make use of edge detection algorithms [17] For the particle selection problem, although the approximate size of the particles is known, it is common that the number of ....

J. Frank. Three-Dimensional Electron Microscopy of MacroMolecular Assemblies. Academic Press, San Diego, CA, 1996.

.... from X ray crystallography [10] distances from nuclear magnetic resonance (NMR) 88] fluorescent energy transfer (FRET) 23] and cross linking [7] surface proximity information from solvent accessibility [57] and chemical probes [69] and molecular surface shape from electron microscopy [31]. Computing the molecular structure from these diverse sources of information can be a challenging undertaking. First, for many molecules, no single source of data is sufficient in quantity and quality to determine the structure completely. For example, exclusively NMRdetermined structures are ....

....Proximity Computing the three dimensional conformation of large biological molecules requires integration of multiple sources of structural data. An example is the 30S ribosome [46] for which there are distances from chemical footprinting [77] molecular surface shape from electron microscopy [31], surface proximity (information about the degrees to which various regions of the molecule are buried within or exposed to the solvent) from sensitivity to chemical probes [69] and other data. The incorporation of distance constraints into most computational techniques is straightforward. ....

J. Frank, Three-Dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press, San Diego, 1996.

....proteins, whicha] functionafifi intriguing,ai very i#cult to crystaX[3M a only limite structuresha ve been etermine . Since traF[dX[fi electron microscopya3F ws for the irect observaser of theaedqF ensity, single pafi]qd angle p ha ag we for thestructura atructu of ribosomea membraq proteins [3]. Single pa[qqq angle p is consi ere to be aa va ntaM] metho for observingstructura chaM a molecula complexes of working proteins instructura biology stu ies of the nextgenera[dX Negaer estaF]3d isa technique for fixinga specimen in va]qF optics withhea vy aq] chemicad ona fineca onpla] Recently, ....

Frank, J., Three-dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press London, 1996.

....variability not present in the crystal (Sosa et al. 1997) Also, visual docking requires the choice of a molecular boundary in the reconstruction volume. Usually, a cutoff density value is chosen for the surface representation, although it is clear that EM images of molecules lack hard boundaries (Frank, 1996). A faithful representation of the molecular surface may even become impossible if static disorder in averaged EM data alters the shape of the surface contour signicantly. E mail address of the corresponding author: wriggers ucsd.edu Abbreviations used: 3D, three dimensional; EM, electron ....

....(Bleiber Hill, 1993) The computations (Figures 2 and 3) required six hours computing time on a Silicon Graphics Indigo 2 workstation. 1250 Quantization of 3D Biological Data experimental density does not strictly correspond to the object density. The voxel histogram (Frank et al. 1991; Frank, 1996) of an image reconstruction of actin from micrographs (Orlova Egelman, 1993) in Figure 3(a) illustrates two general properties of experimental density distributions. First, a pronounced peak at low densities (here shifted to the origin) is due to background scattering. The protein density ....

[Article contains additional citation context not shown here]

Frank, J. (1996). Three-dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press, San Diego.

....is the collection of the image in real space. In X ray crystallography the challenge is to recover the lost information, which is not an issue in electron 2 microscopy. Image formation in electron microscopy is a complex process. The raw images are not faithful representations of the particle [4]. The microscope induces artifacts that need to be corrected. The basis of image formation is the interaction of the electrons with the object. The theory of image formation states that the wave function at the diffraction plane of an electron lens is the Fourier transform of the object s ....

J. Frank. Three-Dimensional Electron Microscopy of Macromolecular Assemblies. Academic Press, 1996.

....voxels of the array has a density value which typically is a small integer in the range 0: 255. Such models are produced, e.g. from two dimensional electron microscopy images (projections) of the virus. The model construction itself is a very challenging problem in computer tomography (see e.g. [3]) Once a model has been constructed, it is of great interest to compare different models against each other and especially to search for known substructures inside the new model. Such a substructure can be, e.g. a protein that is known to occur in the shell of the virus. The substructure can ....

J. Frank. Three--dimensional electron microscopy of macromolecular assemblies. Academic Press, 1996.

No context found.

Joachim Frank. Three-Dimensional Electron Microscopy of Macromolecular Assemblies. Academic Press, 1996.

No context found.

J. Frank, Three-Dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press, 1996.

No context found.

J. Frank. Three--dimensional electron microscopy of macromolecular assemblies. Academic Press, 1996.

No context found.

J. Frank, Three-Dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press, 1996.

No context found.

Joachim Frank. Three-Dimensional Electron Microscopy of Macromolecular Assemblies. Academic Press, 1996.

No context found.

J. Frank, Three Dimensional Electron Microscopy of Macromolecular Assemblies, Academic Press, San Diego, CA, USA, 1996. 644

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC