37ZO

Arabidopsis H2AXa containing nucleosome, Right offset stack

Summary for 37ZO

• Entry DOI: 10.2210/pdb37zo/pdb
• EMDB information: 78669
• Descriptor: Histone H3.1, Histone H4, Probable histone H2AXa, ... (6 entities in total)
• Functional Keywords: nucleosome, chromatin, gene regulation, nuclear protein, nuclear protein-dna complex, nuclear protein/dna
• Biological source: Arabidopsis thaliana (thale cress); More
• Total number of polymer chains: 20
• Total formula weight: 426755.93

Authors

Panigrahi, R.,Edwards, R.,Glover, M. (deposition date: 2026-08-15, release date: 2026-10-28)

Primary citation

Panigrahi, R.,Edwards, R.,Agbagba, N.,Glover, M.
Molecular Architecture of the H2AX-Containing Nucleosome from Arabidopsis.
Cells, 15:-, 2026

PubMed Abstract: Nucleosomes integrate diverse histone variants to organize chromatin and coordinate genome maintenance. In plants, the structural interplay between replication-associated histones and DNA damage-responsive histone variants remains poorly understood. Here, we determine cryogenic electron microscopy structures of an () nucleosome containing the replication-associated histones H2B.6 and H3.1 together with the DNA damage-responsive variant H2AXa. The mononucleosome structure, resolved at 2.73 Å, preserves the canonical nucleosome architecture. Unexpectedly, the reconstituted mononucleosomes formed defined higher-order assemblies in the absence of linker DNA or chemical crosslinking. Two distinct nucleosome-nucleosome arrangements, parallel and right offset, were identified. The right offset closely resembles the human counterpart, whereas the parallel arrangement exhibits slight displacement of H2B structural elements at the inter-nucleosomal interface. Together these structures reveal how a distinct histone composition preserves the canonical nucleosome architecture while supporting multiple defined modes of nucleosome packing, providing structural insights into conserved and divergent features of H2AX-containing chromatin organization across plants and animals.

PubMed: 42882494
DOI: 10.3390/cells15191795

Experimental method

ELECTRON MICROSCOPY (3.45 Å)