7NKX

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

Summary for 7NKX

• Entry DOI: 10.2210/pdb7nkx/pdb
• EMDB information: 12449
• Descriptor: DNA-directed RNA polymerase II subunit RPB1, DNA-directed RNA polymerases I, II, and III subunit RPABC4, Histone H3.2, ... (26 entities in total)
• Functional Keywords: chromatin remodelling, transcription, nucleosome, chromatin
• Biological source: Xenopus laevis (African clawed frog); More
• Total number of polymer chains: 26
• Total formula weight: 1053545.15

Authors

Farnung, L.,Ochmann, M.,Engeholm, M.,Cramer, P. (deposition date: 2021-02-19, release date: 2021-08-25, Last modification date: 2024-07-10)

Primary citation

Farnung, L.,Ochmann, M.,Engeholm, M.,Cramer, P.
Structural basis of nucleosome transcription mediated by Chd1 and FACT.
Nat.Struct.Mol.Biol., 28:382-387, 2021

PubMed 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.

PubMed: 33846633
DOI: 10.1038/s41594-021-00578-6

Experimental method

ELECTRON MICROSCOPY (2.9 Å)