7OHC

Cryo-EM structure of nucleosome core particle composed of the Widom 601 DNA sequence

Summary for 7OHC

• Entry DOI: 10.2210/pdb7ohc/pdb
• EMDB information: 12900
• Descriptor: Histone H3.2, Histone H4, Histone H2A, ... (6 entities in total)
• Functional Keywords: nucleosome, nuclear protein
• Biological source: Xenopus laevis (African clawed frog); More
• Total number of polymer chains: 10
• Total formula weight: 197652.35

Authors

Wang, H.,Cramer, P. (deposition date: 2021-05-10, release date: 2021-07-28, Last modification date: 2024-07-10)

Primary citation

Wang, H.,Xiong, L.,Cramer, P.
Structures and implications of TBP-nucleosome complexes.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: The TATA box-binding protein (TBP) is highly conserved throughout eukaryotes and plays a central role in the assembly of the transcription preinitiation complex (PIC) at gene promoters. TBP binds and bends DNA, and directs adjacent binding of the transcription factors TFIIA and TFIIB for PIC assembly. Here, we show that yeast TBP can bind to a nucleosome containing the Widom-601 sequence and that TBP-nucleosome binding is stabilized by TFIIA. We determine three cryo-electron microscopy (cryo-EM) structures of TBP-nucleosome complexes, two of them containing also TFIIA. TBP can bind to superhelical location (SHL) -6, which contains a TATA-like sequence, but also to SHL +2, which is GC-rich. Whereas binding to SHL -6 can occur in the absence of TFIIA, binding to SHL +2 is only observed in the presence of TFIIA and goes along with detachment of upstream terminal DNA from the histone octamer. TBP-nucleosome complexes are sterically incompatible with PIC assembly, explaining why a promoter nucleosome generally impairs transcription and must be moved before initiation can occur.

PubMed: 34301908
DOI: 10.1073/pnas.2108859118

Experimental method

ELECTRON MICROSCOPY (2.5 Å)