Interaction of 16S rRNA With Protein S4 - a first step to visualization of the assembly of the Escherichia Coli 30S Ribosomal Subunit by Stem

1986 ◽  
Vol 44 ◽  
pp. 296-297
Author(s):  
V. Mandlyan ◽  
G. T. Oostergetel ◽  
J. S. Wall ◽  
J. F. Hainfeld ◽  
M. Boublik
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Large Angle ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Dark Field ◽  
Dimensional Structure ◽  
Radius Of Gyration ◽  
Field Mode ◽  
Transmission Electron

Understanding the mechanism of ribosome assembly and involvement in protein synthesis can be greatly facilitated by elucidation of its three-dimensional structure. The conformation, topography, and Interactions of ribosomal constituent proteins and RNAs can be directly studied by dedicated high resolution scanning transmission electron microscopy (STEM). The high (80%) efficiency in collection of scattered electrons in the dark-field mode makes 1t possible to visualize freezedried unstained specimens at low radiation dose (le/Å2); this minimizes many artifacts inherent in conventional transmission electron microscopy (staining, air-dry1ng, and radiation damage). In addition, the linear proportionality of the large-angle elastically scattered electrons to specimen mass thickness can be used for quantitative determination of molecular weight, mass distribution, and calculation of the apparent radius of gyration (RG), a parameter closely related to the threedimensional structure of the macromolecule.

scholarly journals Transmission electron microscopy analysis of the crystallography of precipitates in Mg–Sn alloys aged at high temperatures

2014 ◽  
Vol 47 (5) ◽  
pp. 1729-1735 ◽  
Author(s):  
Xin Nie ◽  
Yimin Guan ◽  
Dongshan Zhao ◽  
Yu Liu ◽  
Jianian Gui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Dark Field ◽  
Peak Hardness ◽  
Invariant Line ◽  
Orientation Relationships ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Annular Dark Field

The crystallographic orientation relationships (ORs) of precipitated β-Mg2Sn particles in Mg–9.76 wt% Sn alloy aged at 573 K for 5 h, corresponding to its peak hardness, were investigated by advanced transmission electron microscopy (TEM). OR-3 of (110)β//(0001)αand [\overline 111]β//[1\overline 210]αand OR-4 of (110)β//(0001)αand [001]β//[2\overline 1\overline 10]αare the key ORs of β-Mg2Sn particles in the alloy. The proportions of β-Mg2Sn particles exhibiting OR-3 and OR-4 were determined as 75.1 and 24.3%, respectively. Crystallographic factors determined the predominance of OR-3 in the precipitated β-Mg2Sn particles. This mechanism was analyzed by a three-dimensional invariant line model constructed using a transformation matrix in reciprocal space. Models of the interface of precipitated β-Mg2Sn and the α-Mg matrix were constructedviahigh-resolution TEM and atomic resolution high-angle annular dark-field scanning TEM.

scholarly journals In Situ Transmission Electron Microscopy Imaging of Electromigration in Platinum Nanowires

2013 ◽  
Vol 19 (S5) ◽  
pp. 43-48 ◽  
Author(s):  
Maria Rudneva ◽  
Bo Gao ◽  
Ferry Prins ◽  
Qiang Xu ◽  
Herre S.J. van der Zant ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Feedback Control ◽  
Three Dimensional ◽  
Dark Field ◽  
Control Mode ◽  
Microscopy Imaging ◽  
Platinum Nanowires ◽  
Transmission Electron

AbstractIn situ transmission electron microscopy was performed on the electromigration in platinum (Pt) nanowires (14 nm thick, 200 nm wide, and 300 nm long) with and without feedback control. Using the feedback control mode, symmetric electrodes are obtained and the gap usually forms at the center of the Pt nanowire. Without feedback control, asymmetric electrodes are formed, and the gap can occur at any position along the wire. The three-dimensional gap geometries of the electrodes in the Pt nanowire were determined using high-angle annular dark-field scanning transmission electron microscopy; the thickness of the nanowire is reduced from 14 nm to only a few atoms at the edge with a gap of about 5–10 nm.

Three-Dimensional Structure of Helical and Zigzagged Nanowires Using Electron Tomography

2008 ◽  
Vol 1144 ◽  
Author(s):  
Han Sung Kim ◽  
Yoon Myung ◽  
Chang Hyun Kim ◽  
Seung Yong Bae ◽  
Jae-Pyoung Ahn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Helical Structure ◽  
Axial Direction ◽  
Dimensional Structure ◽  
Gan Nanowires ◽  
Transmission Electron

ABSTRACTElectron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional structures of helical or zigzagged GaN, ZnGa2O4 and Zn2SnO4 nanowires. The helical GaN nanowires adopt a helical structure that consists of six equivalent <0-111> growth directions with the axial [0001] direction. The ZnGa2O4 nanosprings have four equivalent <011> growth directions with the [001] axial direction. The zigzagged Zn2SnO4 nanowires consisted of linked rhombohedrons structure having the side edges matched to the <011> direction, and the [111] axial direction.

scholarly journals Three-dimensional reconstruction of an actin bundle.

1988 ◽  
Vol 107 (2) ◽  
pp. 597-611 ◽  
Author(s):  
E S Bullitt ◽  
D J DeRosier ◽  
L M Coluccio ◽  
L G Tilney
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Oblate Spheroid ◽  
Potassium Thiocyanate ◽  
Dimensional Structure ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Dimensional Reconstruction ◽  
Molecular Masses

We present the three-dimensional structure of an actin filament bundle from the sperm of Limulus. The bundle is a motile structure which by changing its twist, converts from a coiled to an extended form. The bundle is composed of actin plus two auxiliary proteins of molecular masses 50 and 60 kD. Fraying the bundle with potassium thiocyanate created three classes of filaments: actin, actin plus the 60-kD protein, and actin plus both the auxiliary proteins. We examined these filaments by transmission electron microscopy and scanning transmission electron microscopy (STEM). Three-dimensional reconstructions from electron micrographs allowed us to visualize the actin subunit and the 60- and 50-kD subunits bound to it. The actin subunit appears to be bilobed with dimensions 70 X 40 X 35 A. The inner lobe of the actin subunit, located at 20 A radius, is a prolate ellipsoid, 50 X 25 A; the outer actin lobe, at 30 A radius, is a 35-A-diam spheroid. Attached to the inner lobe of actin is the 60-kD protein, an oblate spheroid, 55 X 40 A, at 50 A radius. The armlike 50-kD protein, at 55 A radius, links the 60-kD protein on one of actin's twin strands to the outer lobe of the actin subunit on the opposite strand. We speculate that the 60-kD protein may be a bundling protein and that the 50-kD protein may be responsible for the change in twist of the filaments which causes extension of the bundle.

TEM Z-contrast imaging with wide-angle hollow-cone illumination

1990 ◽  
Vol 48 (4) ◽  
pp. 400-401
Author(s):  
J. Bentley ◽  
K. B. Alexander ◽  
Z. L. Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Wide Angle ◽  
Hollow Cone ◽  
Contrast Imaging ◽  
Field Mode ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Z Contrast

High resolution scanning transmission electron microscopy (STEM) images with contrast sensitive to atomic number (Z-contrast) have been obtained with the use of a high-angle annular detector. The equivalent conventional transmission electron microscopy (TEM) dark-field mode reciprocally related to Z-contrast STEM is wide-angle hollow-cone illumination with an on-axis objective aperture. There are two ways to obtain hollow cone illumination; with an annular condenser aperture or by conically scanning the beam tilt coils. As in the case of STEM Z-contrast imaging, resolution with hollow-cone illumination should theoretically be higher than for phase contrast imaging in the same instrument.Philips CM30/STEM, CM12/STEM, and EM400T/FEG/STEM instruments have been used to investigate this imaging technique. The conical illumination dark-field mode is standard on the CM series and was implemented with a hybrid diffraction unit on the EM400. Commercial (SPI Supplies #1780) copper annular apertures with inner and outer diameters of 600 and 900 μm, respectively, spot welded to suitable supports for use as condenser apertures, resulted in cone angles too small to give good Z-contrast in the microprobe mode, because there is still a large diffraction contrast contribution.

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