Structural basis of nucleosome transcription mediated by Chd1 and FACT
| Autor: | Lucas Farnung, Patrick Cramer, Maik Engeholm, Moritz Ochmann |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Transcription Genetic Chromosomal Proteins Non-Histone viruses Saccharomyces cerevisiae Chromatin remodelling RNA polymerase II Article Histones chemistry.chemical_compound Structural Biology Histone H2A Electron microscopy Translocase Nucleosome Molecular Biology biology High Mobility Group Proteins DNA biology.organism_classification Chromatin Assembly and Disassembly Chromatin Nucleosomes Cell biology DNA-Binding Proteins Elongation factor Histone chemistry Multiprotein Complexes Chaperone (protein) biology.protein RNA Polymerase II Transcriptional Elongation Factors Transcription |
| Zdroj: | Nature structural & molecular biology Nature Structural & Molecular Biology |
| Popis: | Efficient transcription of RNA polymerase II (Pol II) through nucleosomes requires the help of various factors. Here we show biochemically that Pol II transcription through a nucleosome is facilitated by the chromatin remodeler Chd1 and the histone chaperone FACT when the elongation factors Spt4/5 and TFIIS are present. We report cryo-EM structures of transcribing Saccharomyces cerevisiae Pol II−Spt4/5−nucleosome complexes with bound Chd1 or FACT. In the first structure, Pol II transcription exposes the proximal histone H2A−H2B dimer that is bound by Spt5. Pol II has also released the inhibitory DNA-binding region of Chd1 that is poised to pump DNA toward Pol II. In the second structure, Pol II has generated a partially unraveled nucleosome that binds FACT, which excludes Chd1 and Spt5. These results suggest that Pol II progression through a nucleosome activates Chd1, enables FACT binding and eventually triggers transfer of FACT together with histones to upstream DNA. Structural and functional analyses of RNA polymerase II−nucleosome complexes reveal how the chromatin remodeler Chd1 and the histone chaperone FACT mediate Pol II transcription through a nucleosome. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|