Zernike phase plate cryoelectron microscopy facilitates single particle analysis of unstained asymmetric protein complexes
| Autor: | Ji-Chau Chang, I-Ping Tu, Wei-Hau Chang, Yen Cheng Lin, Chin-Yu Chen, Jianhua Fu, Holland Cheng, Chi-Fu Yen, Yi-ping Weng, Yi-Min Wu, Michael T.-K. Chiu |
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| Rok vydání: | 2009 |
| Předmět: |
Microscope
Materials science Zernike polynomials PROTEINS Single particle analysis RNA polymerase II Saccharomyces cerevisiae law.invention symbols.namesake law Structural Biology Bacteriophage T7 Microscopy Receptors Transferrin medicine T7 RNA polymerase Molecular Biology Contrast transfer function biology Cryoelectron Microscopy Crystallography Structural biology biology.protein symbols Biophysics Muramidase RNA Polymerase II medicine.drug |
| Zdroj: | Structure (London, England : 1993). 18(1) |
| ISSN: | 1878-4186 |
| Popis: | SummarySingle particle reconstruction from cryoelectron microscopy images, though emerging as a powerful means in structural biology, is faced with challenges as applied to asymmetric proteins smaller than megadaltons due to low contrast. Zernike phase plate can improve the contrast by restoring the microscope contrast transfer function. Here, by exploiting simulated Zernike and conventional defocused cryoelectron microscope images with noise characteristics comparable to those of experimental data, we quantified the efficiencies of the steps in single particle analysis of ice-embedded RNA polymerase II (500 kDa), transferrin receptor complex (290 kDa), and T7 RNA polymerase lysozyme (100 kDa). Our results show Zernike phase plate imaging is more effective as to particle identification and also sorting of orientations, conformations, and compositions. Moreover, our analysis on image alignment indicates that Zernike phase plate can, in principle, reduce the number of particles required to attain near atomic resolution by 10–100 fold for proteins between 100 kDa and 500 kDa. |
| Databáze: | OpenAIRE |
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