EMD-12668

Single-particle
3.1 Å
EMD-12668 Deposition: 24/03/2021
Map released: 28/04/2021
Last modified: 28/04/2021
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-12668

RNA polymerase II-Spt4/5-nucleosome-Chd1 structure - Map C

EMD-12668

Single-particle
3.1 Å
EMD-12668 Deposition: 24/03/2021
Map released: 28/04/2021
Last modified: 28/04/2021
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Saccharomyces cerevisiae
Sample: RNA polymerase II-Spt4/5-Chd1-nucleosome

Deposition Authors: Farnung L, Ochmann M, Engeholm M, Cramer P
Structural basis of nucleosome transcription mediated by Chd1 and FACT.
Farnung L , Ochmann M, Engeholm M, Cramer P
(2021) Nat. Struct. Mol. Biol. , 28 , 382 - 387
PUBMED: 33846633
DOI: doi:10.1038/s41594-021-00578-6
ISSN: 1545-9985
Abstract:
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.