Three-Dimensional Imaging of In Situ Specimens with Low-Dose Electron Tomography to Analyze Protein Conformation

2004 ◽  
Vol 2 (5) ◽  
pp. 561-567 ◽  
Author(s):  
Martina Banyay ◽  
Fredrik Gilstring ◽  
Elenor Hauzenberger ◽  
Lars-Göran Öfverstedt ◽  
Anders B. Eriksson ◽  
...  
2004 ◽  
Vol 2 (5) ◽  
pp. 561-567
Author(s):  
Martina Banyay ◽  
Fredrik Gilstring ◽  
Elenor Hauzenberger ◽  
Lars-Göran Öfverstedt ◽  
Anders B. Eriksson ◽  
...  

2022 ◽  
Author(s):  
Jie E Yang ◽  
Matthew R Larson ◽  
Bryan S Sibert ◽  
Joseph Y Kim ◽  
Daniel Parrell ◽  
...  

Imaging large fields of view while preserving high-resolution structural information remains a challenge in low-dose cryo-electron tomography. Here, we present robust tools for montage electron tomography tailored for vitrified specimens. The integration of correlative cryo-fluorescence microscopy, focused-ion beam milling, and micropatterning produces contextual three-dimensional architecture of cells. Montage tilt series may be processed in their entirety or as individual tiles suitable for sub-tomogram averaging, enabling efficient data processing and analysis.


2020 ◽  
Author(s):  
Danielle Grotjahn ◽  
Saikat Chowdhury ◽  
Gabriel C. Lander

AbstractCryo-electron tomography is a powerful biophysical technique enabling three-dimensional visualization of complex biological systems. Macromolecular targets of interest identified within cryo-tomograms can be computationally extracted, aligned, and averaged to produce a better-resolved structure through a process called subtomogram averaging (STA). However, accurate alignment of macromolecular machines that exhibit extreme structural heterogeneity and conformational flexibility remains a significant challenge with conventional STA approaches. To expand the applicability of STA to a broader range of pleomorphic complexes, we developed a user-guided, focused refinement approach that can be incorporated into the standard STA workflow to facilitate the robust alignment of particularly challenging samples. We demonstrate that it is possible to align visually recognizable portions of multi-subunit complexes by providing a priori information regarding their relative orientations within cryo-tomograms, and describe how this strategy was applied to successfully elucidate the first three-dimensional structure of the dynein-dynactin motor protein complex bound to microtubules. Our approach expands the application of STA for solving a more diverse range of heterogeneous biological structures, and establishes a conceptual framework for the development of automated strategies to deconvolve the complexity of crowded cellular environments and improve in situ structure determination technologies.


2007 ◽  
Vol 90 (9) ◽  
pp. 093111 ◽  
Author(s):  
Jong-Bong Park ◽  
Jun Ho Lee ◽  
Hye-Ran Choi

Polymer ◽  
2005 ◽  
Vol 46 (12) ◽  
pp. 4440-4446 ◽  
Author(s):  
Shinzo Kohjiya ◽  
Astushi Katoh ◽  
Junichi Shimanuki ◽  
Toshinori Hasegawa ◽  
Yuko Ikeda

2008 ◽  
Vol 183 (5) ◽  
pp. 923-932 ◽  
Author(s):  
Khanh Huy Bui ◽  
Hitoshi Sakakibara ◽  
Tandis Movassagh ◽  
Kazuhiro Oiwa ◽  
Takashi Ishikawa

The inner dynein arm regulates axonemal bending motion in eukaryotes. We used cryo-electron tomography to reconstruct the three-dimensional structure of inner dynein arms from Chlamydomonas reinhardtii. All the eight different heavy chains were identified in one 96-nm periodic repeat, as expected from previous biochemical studies. Based on mutants, we identified the positions of the AAA rings and the N-terminal tails of all the eight heavy chains. The dynein f dimer is located close to the surface of the A-microtubule, whereas the other six heavy chain rings are roughly colinear at a larger distance to form three dyads. Each dyad consists of two heavy chains and has a corresponding radial spoke or a similar feature. In each of the six heavy chains (dynein a, b, c, d, e, and g), the N-terminal tail extends from the distal side of the ring. To interact with the B-microtubule through stalks, the inner-arm dyneins must have either different handedness or, more probably, the opposite orientation of the AAA rings compared with the outer-arm dyneins.


2019 ◽  
Author(s):  
K. Tanuj Sapra ◽  
Zhao Qin ◽  
Anna Dubrovsky-Gaupp ◽  
Ueli Aebi ◽  
Daniel J. Müller ◽  
...  

AbstractThe nuclear lamina – a meshwork of intermediate filaments termed lamins – functions as a mechanotransduction interface between the extracellular matrix and the nucleus via the cytoskeleton. Although lamins are primarily responsible for the mechanical stability of the nucleus in multicellular organisms, in situ characterization of lamin filaments under tension has remained elusive. Here, we apply an integrative approach combining atomic force microscopy, cryo-electron tomography, network analysis, and molecular dynamics simulations to directly measure the mechanical response of single lamin filaments in its three-dimensional meshwork. Endogenous lamin filaments portray non-Hookean behavior – they deform reversibly under a force of a few hundred picoNewtons and stiffen at nanoNewton forces. The filaments are extensible, strong and tough, similar to natural silk and superior to the synthetic polymer Kevlar®. Graph theory analysis shows that the lamin meshwork is not a random arrangement of filaments but the meshwork topology follows ‘small world’ properties. Our results suggest that the lamin filaments arrange to form a robust, emergent meshwork that dictates the mechanical properties of individual lamin filaments. The combined approach provides quantitative insights into the structure-function organization of lamins in situ, and implies a role of meshwork topology in laminopathies.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Swetha Vijayakrishnan ◽  
Marion McElwee ◽  
Colin Loney ◽  
Frazer Rixon ◽  
David Bhella

Abstract Cryo electron microscopy (cryo-EM), a key method for structure determination involves imaging purified material embedded in vitreous ice. Images are then computationally processed to obtain three-dimensional structures approaching atomic resolution. There is increasing interest in extending structural studies by cryo-EM into the cell, where biological structures and processes may be imaged in context. The limited penetrating power of electrons prevents imaging of thick specimens (> 500 nm) however. Cryo-sectioning methods employed to overcome this are technically challenging, subject to artefacts or involve specialised and costly equipment. Here we describe the first structure of herpesvirus capsids determined by sub-tomogram averaging from nuclei of eukaryotic cells, achieved by cryo-electron tomography (cryo-ET) of re-vitrified cell sections prepared using the Tokuyasu method. Our reconstructions confirm that the capsid associated tegument complex is present on capsids prior to nuclear egress. We demonstrate that this method is suited to both 3D structure determination and correlative light/electron microscopy, thus expanding the scope of cryogenic cellular imaging.


Author(s):  
C.L. Woodcock ◽  
R.A. Horowitz ◽  
D.A. Agard

Electron tomography is being used to understand the 3D organization of chromatin in situ. As demonstrated previously, the nuclei of Patiria miniata (starfish) sperm contain particularly well-defined chromatin fibers. These studies are being extended through the analysis of 3D reconstructions of material embedded at low temperature in Lowicryl K11M and contrasted with osmium ammine-B, which preferentially stains nucleic acids. Tilt series of sections were recorded at 150KV, over an angular range of +/−75° and tilt increment of 2.5° using a Philips EM430. Image data were collected directly using a 1024x1024 CCD array with 2x2 binning to give a final pixel size of 1.3nm. Gold beads deposited on the sections were used for alignment, and reconstruction was by weighted back projection. Six volumes totalling 0.48um and containing numerous chromatin fibers have been examined utilizing Voxel View (Vital Images, Fairfield Iowa) software running on a Silicon Graphics Iris 4D workstation.


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