Structural basis of meiotic chromosome synaptic elongation through hierarchical fibrous assembly of SYCE2-TEX12
| Autor: | James M. Dunce, Owen R. Davies, Lucy J Salmon |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
double-strand break
intermediate filaments Cell Cycle Proteins Crystallography X-Ray chiasmata TEX12 Chromosome (genetic algorithm) Meiosis Structural Biology biophysics coiled-coil Homologous chromosome Humans Vimentin meiosis Cytoskeleton Protein Structure Quaternary Intermediate filament Molecular Biology X-ray crystallography Coiled coil Synaptonemal Complex Chemistry synaptonemal complex Synapsis SYCE2 self-assembly Lamins Chromosome Pairing Cytoskeletal Proteins Synaptonemal complex chromosome structure small-angle X-ray scattering Biophysics Keratins Elongation Lamin Macromolecule |
| Zdroj: | Dunce, J, Salmon, L & Davies, O R 2021, ' Structural basis of meiotic chromosome synaptic elongation through hierarchical fibrous assembly of SYCE2-TEX12 ', Nature Structural & Molecular Biology, vol. 28, pp. 681–693 . https://doi.org/10.1038/s41594-021-00636-z |
| DOI: | 10.1101/2020.12.30.424799 |
| Popis: | The supramolecular structure of the synaptonemal complex (SC) mediates homologous chromosome synapsis and facilitates the formation of genetic crossovers during meiosis. The mammalian SC is formed of eight coiled-coil proteins which interact in specific subcomplexes and self-assemble into distinct macromolecular arrays that fulfil specific aspects of the SC’s dynamic functional architecture. Here, we report the structure of SC subcomplex SYCE2-TEX12 and its mechanism of self-assembly into fibres that define the SC’s midline longitudinal structure. X-ray crystal structures, electron microscopy, biophysical and mutational analyses reveal that SYCE2-TEX12 is assembled from 2:2 complexes in which TEX12 chains are positioned at either end of a rod-like SYCE2 dimer. These molecular building-blocks assemble laterally into 4:4 complexes, and longitudinally into fibres of potentially limitless length, which acts as string-like threads that wind around one another in intertwined fibres of up to 40-nm in width and several micrometres in length. This hierarchical assembly mechanism is reminiscent of intermediate filament proteins and results in SYCE2-TEX12 fibres that can span the entire chromosome length, thereby providing the underpinning structural support for SC elongation during meiotic chromosome synapsis. |
| Databáze: | OpenAIRE |
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