scholarly journals Structure of the ciliary axoneme at nanometer resolution reconstructed by TYGRESS

2018 ◽  
Author(s):  
Kangkang Song ◽  
Zhiguo Shang ◽  
Xiaofeng Fu ◽  
Xiaochu Lou ◽  
Nikolaus Grigorieff ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hybrid Method ◽  
Atomic Resolution ◽  
Signal Loss ◽  
Nanometer Resolution ◽  
Cryo Electron Microscopy ◽  
Microscopy Method ◽  
Subtomogram Averaging ◽  
Electron Microscopy Method ◽  
Crowded Environments

AbstractThe resolution of subtomogram averages calculated from cryo-electron tomograms (cryo-ET) of crowded cellular environments is often limited due to signal loss in, and misalignment of the subtomograms. In contrast, single-particle cryo-electron microcopy (SP-cryo-EM) routinely reaches near-atomic resolution of isolated complexes. We developed a novel hybrid-method called “TomographY-Guided 3D REconstruction of Subcellular Structures” (TYGRESS) that combines cryo-ET with SP-cryo-EM to achieve close-to-nanometer resolution of complexes inside crowded environments. Using TYGRESS, we determined the native 3D structures of the intact ciliary axoneme with up to 12 Å resolution. These results reveal many structures and details that were not visible by cryo-ET. TYGRESS is generally applicable to cellular complexes that are amenable to subtomogram averaging, bringing us a step closer to (pseudo-)atomic models of cells.One Sentence SummaryA hybrid cryo-electron microscopy method reveals subcellular structures at unprecedented resolution.

Envelope structure of semliki forest virus reconstructed from projections of randomly oriented single particles visualized by cryo-electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 174-175
Author(s):  
R.H. Vogel ◽  
S.W. Provencher ◽  
C.-H. von Bonsdorff ◽  
M. Adrian ◽  
J. Dubochet
Keyword(s):  
Electron Microscopy ◽  
Phase Contrast ◽  
Semliki Forest Virus ◽  
Atomic Resolution ◽  
Single Particles ◽  
Basic Principles ◽  
Enveloped Viruses ◽  
Cryo Electron Microscopy ◽  
Microscopy Method ◽  
Electron Microscopy Method

The basic principles of the architecture of many viral protein shells are now well established and the structure of several viruses have been elucidated to atomic resolution. Enveloped viruses, like Semliki Forest virus (SFV), have been more difficult to study because they resist crystallization and are easily deformed when prepared for electron microscopy. The latter limitation has been coped with by using a cryo-electron microscopy method in which unfixed and unstained viruses are observed in an unsupported thin layer of vitrified suspension. The appearance of the virus depends strongly on the focus (Fig. 1), because, unlike in conventionally stained specimens, the contrast is essentially due to phase contrast. The focus values of the four micrographs in the series, which were used for the reconstruction, have been chosen to give an optimal coverage of the information contained in the specimen (Fig. 2).

Cryo-EM structure of the mammalian ATP synthase tetramer bound with inhibitory protein IF1

Science ◽  
2019 ◽  
Vol 364 (6445) ◽  
pp. 1068-1075 ◽  
Author(s):  
Jinke Gu ◽  
Laixing Zhang ◽  
Shuai Zong ◽  
Runyu Guo ◽  
Tianya Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Atp Synthase ◽  
Mammalian Cells ◽  
Low Ph ◽  
Inhibitory Protein ◽  
Cryo Electron Microscopy ◽  
The Matrix ◽  
Microscopy Method ◽  
Electron Microscopy Method

The mitochondrial adenosine triphosphate (ATP) synthase produces most of the ATP required by mammalian cells. We isolated porcine tetrameric ATP synthase and solved its structure at 6.2-angstrom resolution using a single-particle cryo–electron microscopy method. Two classical V-shaped ATP synthase dimers lie antiparallel to each other to form an H-shaped ATP synthase tetramer, as viewed from the matrix. ATP synthase inhibitory factor subunit 1 (IF1) is a well-known in vivo inhibitor of mammalian ATP synthase at low pH. Two IF1 dimers link two ATP synthase dimers, which is consistent with the ATP synthase tetramer adopting an inhibited state. Within the tetramer, we refined structures of intact ATP synthase in two different rotational conformations at 3.34- and 3.45-Å resolution.

scholarly journals Direct TEM observation of the “acanthite α-Ag2S–argentite β-Ag2S” phase transition in a silver sulfide nanoparticle

2019 ◽  
Vol 1 (4) ◽  
pp. 1581-1588 ◽  
Author(s):  
S. I. Sadovnikov ◽  
E. Yu. Gerasimov
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Silver Sulfide ◽  
Transmission Electron ◽  
Silver Sulfide Nanoparticles ◽  
Microscopy Method ◽  
Electron Microscopy Method ◽  
First Time

For the first time, the α-Ag2S (acanthite)–β-Ag2S (argentite) phase transition in a single silver sulfide nanoparticles has been observed in situ using a high-resolution transmission electron microscopy method in real time.

scholarly journals A resolution record for cryoEM

2021 ◽  
Vol 10 ◽  
Author(s):  
Jonathan Ashmore ◽  
Bridget Carragher ◽  
Peter B Rosenthal ◽  
William Weis
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Structure Determination ◽  
Test Specimen ◽  
Structural Information ◽  
Atomic Resolution ◽  
Fast Growing ◽  
Cryo Electron Microscopy ◽  
New Instrument ◽  
Resolution Structure

Cryo electron microscopy (cryoEM) is a fast-growing technique for structure determination. Two recent papers report the first atomic resolution structure of a protein obtained by averaging images of frozen-hydrated biomolecules. They both describe maps of symmetric apoferritin assemblies, a common test specimen, in unprecedented detail. New instrument improvements, different in the two studies, have contributed better images, and image analysis can extract structural information sufficient to resolve individual atomic positions. While true atomic resolution maps will not be routine for most proteins, the studies suggest structures determined by cryoEM will continue to improve, increasing their impact on biology and medicine.

Forge Wednesday Roundup - June 10, 2020

2021 ◽  
Author(s):  
H.L. Cu Si
Keyword(s):  
Electron Microscopy ◽  
Facial Recognition ◽  
Academic Research ◽  
Atomic Resolution ◽  
Rapa Nui ◽  
Social Distancing ◽  
Cryo Electron Microscopy

In today’s Roundup: COVID is still with us; pair of papers quantifies effects of social distancing; IBM bails on facial recognition, warns of harms; questioning “collapse” of Rapa Nui; attention turns to antibodies for COVID-19 therapies; WHO walks back confusing statement on asymptomatic COVID transmission; cryo-electron microscopy reveals proteins at atomic resolution; unstoppable newsbot runs amok, propagates bias; exploring the lure of misinformation; academic research goes on strike against racism; much more...

Features of Wear of Abrasive Grains Depending on Microcuttings Speed of Steels

2016 ◽  
Vol 674 ◽  
pp. 189-194 ◽  
Author(s):  
Margarita A. Skotnikova ◽  
Galina V. Tsvetkova ◽  
Nikolay A. Krylov ◽  
Evgeniy K. Ivanov ◽  
Viktoriy V. Medvedeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Layer ◽  
Thin Surface Layer ◽  
Abrasive Grains ◽  
Microscopy Method ◽  
Scanning Electron Microscopy Method ◽  
Electron Microscopy Method ◽  
Scanning Electron ◽  
Alloy Titanium

In this article by the example of two abrasive materials from oxide of aluminum and nitride of boron, the processes developing in a thin surface layer between a grain of abrasive and the material, processed by microcutting with speeds of 40 and 160 m/s, the preforms from armko-iron, steels R18, 45, H18N10T and alloy titanium VT6 are investigated, using the scanning electron microscopy method.

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