Three-dimensional reconstruction from dark-field electron micrographs of macromolecules at random unknown angles
| Autor: | N.A. Farrow, F.P. Ottensmeyer |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Proceedings, annual meeting, Electron Microscopy Society of America. 50:1058-1059 |
| ISSN: | 2690-1315 0424-8201 |
| DOI: | 10.1017/s0424820100129929 |
| Popis: | Electron microscopy produces 2D images of 3D objects with resolutions generally from about 2-5 nm for stained or shadowed specimens, to as good as 0.3-0.5 nm for unstained specimens using bright field or dark field techniques. Many groups have worked on methods that attempt to recover the 3D information that is lost in the 2D representation. We have built on and extended previous techniques, and report here the development and application of a robust, unbiased quaternion-based alignment procedure to facilitate 3D reconstruction of molecules imaged at random unknown orientations. The approach is demonstrated using dark field electron micrographs of the Klenow fragment of DNA polymerase.Many procedures for 3D structure determination using electron microscopy have been reported. For fairly simple, small proteins it has been possible to derive a correct high resolution 3D structure by folding the known amino acid chain using dark field electron micrographs as geometric constraintse.g.. However, in general the reconstruction of a 3D density distribution requires knowledge of the relative orientation of different projection images of the object. To determine such orientations a variety of techniques have been employed, frequently adapted to the specimen of interest. |
| Databáze: | OpenAIRE |
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