The correlation averaging of a regularly arranged bacterial cell envelope protein

Saxton, W. O.; Baumeister, W.

doi:10.1111/j.1365-2818.1982.tb00405.x

Cited by 848 publications

(523 citation statements)

References 19 publications

(16 reference statements)

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“…The largest class containing 1200 images showing the complex in the same orientation was analysed further. For the final class average, the resolution determined by Fourier ring correlation [36] was estimated to be 22 Å , with a cut off criterion five times the noise correlation. For analyzing the existing variability in this subset of images a classification with a neural network algorithm [33] using an array of 5 · 5 nodes was performed.…”

Section: 4mentioning

confidence: 99%

Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

et al. 2006

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The F 1 F 0 ATP synthase has been purified from the hyperthermophilic eubacterium Aquifex aeolicus and characterized. Its subunits have been identified by MALDI-mass spectrometry through peptide mass fingerprinting and MS/MS. It contains the canonical subunits a, b, c, d and e of F 1 and subunits a and c of F 0 . Two versions of the b subunit were found, which show a low sequence homology to each other. Most likely they form a heterodimer. An electron microscopic single particle analysis revealed clear structural details, including two stalks connecting F 1 and F 0 . In several orientations the central stalk appears to be tilted and/or kinked. It is unclear whether there is a direct connection between the peripheral stalk and the d subunit.

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Section: 4mentioning

confidence: 99%

Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

et al. 2006

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“…1E) is a simple average of the 80% of the particles having the best cross-correlation coefficients. Its resolution was calculated by Fourier shell correlation of two averages (Saxton and Baumeister, 1982), each derived from a randomly chosen half of the selected particles (Fig. 1C).…”

Section: Reconstruction Of Poliovirus-receptor-liposome Complexmentioning

confidence: 99%

Single particle cryoelectron tomography characterization of the structure and structural variability of poliovirus–receptor–membrane complex at 30 Å resolution

Bostina

Bubeck

Schwartz

et al. 2007

Journal of Structural Biology

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As a long-term goal we want to use cryoelectron tomography to understand how non-enveloped viruses, such as picornaviruses, enter cells and translocate their genomes across membranes. To this end, we developed new image-processing tools using an in vitro system to model viral interactions with membranes. The complex of poliovirus with its membrane-bound receptors was reconstructed by averaging multiple sub-tomograms, thereby producing three-dimensional maps of surprisingly high resolution (30Å). Recognizable images of the complex could be produced by averaging as few as 20 copies. Additionally, model-free reconstructions of free poliovirus particles, clearly showing the major surface features, could be calculated from 60 virions. All calculations were designed to avoid artifacts caused by missing information typical for tomographic data ("missing wedge"). To investigate structural and conformational variability we applied a principal component analysis classification to specific regions. We show that the missing wedge causes a bias in classification, and that this bias can be minimized by supplementation with data from the Fourier transform of the averaged structure. After classifying images of the receptor into groups with high similarity, we were able to see differences in receptor density consistent with the known variability in receptor glycosylation.

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“…The analysis of resolution was done using Fourier Shell Correlation (FSC) curves (FSC is a 3D version of Fourier Ring Correlation measure [23]). For each 3D reconstruction all the input projections were divided randomly into two equal subsets, for each subset a 3D reconstruction was calculated, and these two volumes were compared in Fourier space using FSC curves (Fig.…”

Section: Application To Energy-filtered Images Of the 70s E Coli Ribmentioning

confidence: 99%

Three-Dimensional Reconstruction with Contrast Transfer Function Correction from Energy-Filtered Cryoelectron Micrographs: Procedure and Application to the 70SEscherichia coliRibosome

Zhu

Penczek

Schröder

et al. 1997

Journal of Structural Biology

147

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Cryo-electron microscopy provides the means to quantitatively study macromolecules in their native state. However, the original mass distribution of the macromolecule is distorted by the contrast transfer function (CTF) of the electron microscope. In addition, the zeros of the CTF put a practical limit on the resolution that can be achieved. Substantial improvement to the quality of the results can be accomplished by collecting the data using a series of defocus settings. Such data sets can be combined and the resolution can be extended beyond the first zero of the CTF. This procedure can be applied either at the stage of raw data, or more effectively at the stage of reconstructed volumes which have a high signal-to-noise ratio as a result of averaging over many projections. A method of threedimensional (3D) reconstruction that combines an algebraic, iterative 3D reconstruction technique with CTF correction is proposed. The potential to incorporate a priori knowledge into the reconstruction process is discussed. This approach was used to obtain a 3D reconstruction of the E. coli 70S ribosome from energy-filtered cryo-images.

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The correlation averaging of a regularly arranged bacterial cell envelope protein

Cited by 848 publications

References 19 publications

Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

Single particle cryoelectron tomography characterization of the structure and structural variability of poliovirus–receptor–membrane complex at 30 Å resolution

Three-Dimensional Reconstruction with Contrast Transfer Function Correction from Energy-Filtered Cryoelectron Micrographs: Procedure and Application to the 70SEscherichia coliRibosome

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The correlation averaging of a regularly arranged bacterial cell envelope protein

Cited by 848 publications

References 19 publications

Biochemical and electron microscopic characterization of the F1F0 ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

Biochemical and electron microscopic characterization of the F1F0 ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

Single particle cryoelectron tomography characterization of the structure and structural variability of poliovirus–receptor–membrane complex at 30 Å resolution

Three-Dimensional Reconstruction with Contrast Transfer Function Correction from Energy-Filtered Cryoelectron Micrographs: Procedure and Application to the 70SEscherichia coliRibosome

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Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus

Biochemical and electron microscopic characterization of the F₁F₀ ATP Synthase from the hyperthermophilic eubacterium Aquifex aeolicus