Cryo-Electron Microscopy of Photosystem II: Towards a High-Resolution Structure

1995 ◽  
pp. 2273-2276 ◽  
Author(s):  
Svetla Stoylova ◽  
Paul McPhie ◽  
Toby D. Flint ◽  
Robert C. Ford ◽  
Andreas Holzenburg
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Photosystem Ii ◽  
Cryo Electron Microscopy ◽  
High Resolution Structure ◽  
Resolution Structure

scholarly journals Rapid high-resolution structure analysis of small, biotechnologically relevant enzymes by cryo-electron microscopy

2021 ◽  
Author(s):  
Nicole Dimos ◽  
Carl P.O. Helmer ◽  
Andrea M. Chanique ◽  
Markus C. Wahl ◽  
Robert Kourist ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Biology ◽  
Structure Analysis ◽  
Cryo Electron Microscopy ◽  
High Resolution Structure ◽  
Fast Development ◽  
Pharmaceutical Industries ◽  
Exquisite Specificity ◽  
Resolution Structure

Enzyme catalysis has emerged as a key technology for developing efficient, sustainable processes in the chemical, biotechnological and pharmaceutical industries. Plants provide large and diverse pools of biosynthetic enzymes that facilitate complex reactions, such as the formation of intricate terpene carbon skeletons, with exquisite specificity. High-resolution structural analysis of these enzymes is crucial to understand their mechanisms and modulate their properties by targeted engineering. Although cryo-electron microscopy (cryo-EM) has revolutionized structural biology, its applicability to high-resolution structure analysis of comparatively small enzymes is so far largely unexplored. Here, we show that cryo-EM can reveal the structures of ~120 kDa plant borneol dehydrogenases at or below 2 Å resolution, paving the way for the fast development of new biocatalysts that provide access to bioactive terpenes and terpenoids.

scholarly journals High-resolution structure of the Shigella type-III secretion needle by solid-state NMR and cryo-electron microscopy

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Jean-Philippe Demers ◽  
Birgit Habenstein ◽  
Antoine Loquet ◽  
Suresh Kumar Vasa ◽  
Karin Giller ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
High Resolution ◽  
Type Iii Secretion ◽  
Solid State Nmr ◽  
Type Iii ◽  
Cryo Electron Microscopy ◽  
High Resolution Structure ◽  
Resolution Structure

scholarly journals Comparing the Folds of Prions and Other Pathogenic Amyloids

Pathogens ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 50 ◽  
Author(s):  
José Flores-Fernández ◽  
Vineet Rathod ◽  
Holger Wille
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Amyloid Β ◽  
Paired Helical Filaments ◽  
X Ray ◽  
Cryo Electron Microscopy ◽  
Incompatibility System ◽  
High Resolution Structure ◽  
Jakob Disease ◽  
Resolution Structure

Pathogenic amyloids are the main feature of several neurodegenerative disorders, such as Creutzfeldt–Jakob disease, Alzheimer’s disease, and Parkinson’s disease. High resolution structures of tau paired helical filaments (PHFs), amyloid-β(1-42) (Aβ(1-42)) fibrils, and α-synuclein fibrils were recently reported using cryo-electron microscopy. A high-resolution structure for the infectious prion protein, PrPSc, is not yet available due to its insolubility and its propensity to aggregate, but cryo-electron microscopy, X-ray fiber diffraction, and other approaches have defined the overall architecture of PrPSc as a 4-rung β-solenoid. Thus, the structure of PrPSc must have a high similarity to that of the fungal prion HET-s, which is part of the fungal heterokaryon incompatibility system and contains a 2-rung β-solenoid. This review compares the structures of tau PHFs, Aβ(1-42), and α-synuclein fibrils, where the β-strands of each molecule stack on top of each other in a parallel in-register arrangement, with the β-solenoid folds of HET-s and PrPSc.

scholarly journals High-resolution structure determination of sub-100 kilodalton complexes using conventional cryo-EM

2018 ◽  
Author(s):  
Mark A. Herzik ◽  
Mengyu Wu ◽  
Gabriel C. Lander
Keyword(s):  
High Resolution ◽  
Structure Determination ◽  
Drug Target ◽  
Phase Plate ◽  
Biological Macromolecules ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
High Resolution Structure ◽  
Resolution Structure

Determining high-resolution structures of biological macromolecules with masses of less than 100 kilodaltons (kDa) has long been a goal of the cryo-electron microscopy (cryo-EM) community. While the Volta Phase Plate has enabled cryo-EM structure determination of biological specimens of this size range, use of this instrumentation is not yet fully automated and can present technical challenges. Here, we show that conventional defocus-based cryo-EM methodologies can be used to determine the high-resolution structures of specimens amassing less than 100 kDa using a transmission electron microscope operating at 200 keV coupled with a direct electron detector. Our ~2.9 Å structure of alcohol dehydrogenase (82 kDa) proves that bound ligands can be resolved with high fidelity, indicating that these methodologies can be used to investigate the molecular details of drug-target interactions. Our ~2.8 Å and ~3.2 Å resolution structures of methemoglobin demonstrate that distinct conformational states can be identified within a dataset for proteins as small as 64 kDa. Furthermore, we provide the first sub-nanometer cryo-EM structure of a protein smaller than 50 kDa.

scholarly journals High-resolution cryo-electron microscopy structure of photosystem II from the mesophilic cyanobacterium, Synechocystis sp. PCC 6803

2021 ◽  
Vol 119 (1) ◽  
pp. e2116765118
Author(s):  
Christopher J. Gisriel ◽  
Jimin Wang ◽  
Jinchan Liu ◽  
David A. Flesher ◽  
Krystle M. Reiss ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Photosystem Ii ◽  
Water Oxidation ◽  
Genetic Manipulation ◽  
Water Channel ◽  
Global Scale ◽  
Cryo Electron Microscopy ◽  
C Terminus ◽  
Pcc 6803

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a high-resolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the D1 subunit is flexible, some waters near the active site are partially occupied, and differences in the PsbV subunit block the Large (O1) water channel. These features strongly influence the structural picture of PSII, especially as it pertains to the mechanism of water oxidation.

High-Resolution Cryo-Electron Microscopy of Two-Dimensional Protein Crystals

1990 ◽  
Vol 48 (1) ◽  
pp. 84-85
Author(s):  
F. Zemlin ◽  
E. Beckmann
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Radiation Damage ◽  
Protein Crystals ◽  
Objective Lens ◽  
Two Dimensional ◽  
Cryo Electron Microscopy ◽  
Specimen Temperature ◽  
High Resolution Structure ◽  
Long Time

The task in investigating the structure of crystals is to measure the Fourier coefficients in amplitude and phase. Electron crystallography, i.e. electron diffraction combined with electron-microscopical imaging, is a straigthforward method, because there is a priori no “phase problem”. But radiation damage during electron exposure was for a long time an absolutely unbridgeable chasm on the way to high-resolution structure research of two-dimensional protein crystals by electron microscopy. Now, using cryo-electron microscopy and computer image processing, it has been proven possible to overcome this difficulty and achieve high resolution.Here we present a rough description of the recording procedure. We used a helium-cooled superconducting objective lens with 4.5 K specimen temperature, but the procedure should also be applicable at higher specimen temperatures. The radiation damage is reduced at low specimen temperature, but unfortunately there still remains a remarkable deterioration of the crystal with increasing dose, which means that minimum exposure is advisable.

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