7M1X

Cryo-EM Structure of Nucleosome containing mouse histone variant H2A.Z

Summary for 7M1X

• Entry DOI: 10.2210/pdb7m1x/pdb
• EMDB information: 23626
• Descriptor: DNA (136-MER), Histone H3, Histone H4, ... (6 entities in total)
• Functional Keywords: chromatin, nucleosome, histone variant, epigenetics, transcription, dna binding protein, dna binding protein-dna complex, dna binding protein/dna
• Biological source: unidentified; More
• Total number of polymer chains: 10
• Total formula weight: 199675.21

Authors

Tan, D.,Lewis, T. (deposition date: 2021-03-15, release date: 2021-09-29, Last modification date: 2024-11-13)

Primary citation

Lewis, T.S.,Sokolova, V.,Jung, H.,Ng, H.,Tan, D.
Structural basis of chromatin regulation by histone variant H2A.Z.
Nucleic Acids Res., 49:11379-11391, 2021

PubMed Abstract: The importance of histone variant H2A.Z in transcription regulation has been well established, yet its mechanism-of-action remains enigmatic. Conflicting evidence exists in support of both an activating and a repressive role of H2A.Z in transcription. Here we report cryo-electron microscopy (cryo-EM) structures of nucleosomes and chromatin fibers containing H2A.Z and those containing canonical H2A. The structures show that H2A.Z incorporation results in substantial structural changes in both nucleosome and chromatin fiber. While H2A.Z increases the mobility of DNA terminus in nucleosomes, it simultaneously enables nucleosome arrays to form a more regular and condensed chromatin fiber. We also demonstrated that H2A.Z's ability to enhance nucleosomal DNA mobility is largely attributed to its characteristic shorter C-terminus. Our study provides the structural basis for H2A.Z-mediated chromatin regulation, showing that the increase flexibility of the DNA termini in H2A.Z nucleosomes is central to its dual-functions in chromatin regulation and in transcription.

PubMed: 34643712
DOI: 10.1093/nar/gkab907

Experimental method

ELECTRON MICROSCOPY (3.7 Å)