Structure of mitotic chromosomes.
| Autor: | Beel AJ; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA., Azubel M; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA. Electronic address: mazubel@stanford.edu., Matteï PJ; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA., Kornberg RD; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA. |
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| Jazyk: | angličtina |
| Zdroj: | Molecular cell [Mol Cell] 2021 Nov 04; Vol. 81 (21), pp. 4369-4376.e3. Date of Electronic Publication: 2021 Sep 13. |
| DOI: | 10.1016/j.molcel.2021.08.020 |
| Abstrakt: | Chromatin fibers must fold or coil in the process of chromosome condensation. Patterns of coiling have been demonstrated for reconstituted chromatin, but the actual trajectories of fibers in condensed states of chromosomes could not be visualized because of the high density of the material. We have exploited partial decondensation of mitotic chromosomes to reveal their internal structure at sub-nucleosomal resolution by cryo-electron tomography, without the use of stains, fixatives, milling, or sectioning. DNA gyres around nucleosomes were visible, allowing the nucleosomes to be identified and their orientations to be determined. Linker DNA regions were traced, revealing the trajectories of the chromatin fibers. The trajectories were irregular, with almost no evidence of coiling and no short- or long-range order of the chromosomal material. The 146-bp core particle, long known as a product of nuclease digestion, is identified as the native state of the nucleosome, with no regular spacing along the chromatin fibers. Competing Interests: Declaration of interests The authors declare no competing financial interests. (Copyright © 2021 Elsevier Inc. All rights reserved.) |
| Databáze: | MEDLINE |
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