Back

Cryo-EM reveals open and closed Asgard chromatin assemblies

Ranawat, H. M.; Cajili, M. K. M.; Lopez-Barbosa, N.; Quail, T.; Dame, R. T.; Dodonova, S. O.

2025-05-26 biophysics
10.1101/2025.05.24.653377 bioRxiv
Show abstract

Asgards are the closest archaeal relatives of eukaryotes, representing an important step in chromatin evolution. However, their chromatin organization has remained enigmatic until now. In this study, we present the first structures of Asgard chromatin assemblies formed by the Hodarchaeal histone HHoB. Our high-resolution cryo-EM structures reveal that this Asgard histone assembles into compact "closed" and into extended "open" hypernucleosomes. Thus the closed hypernucleosome conformation is conserved across archaeal lineages, while the open conformation resembles a eukaryotic H3-H4 octasome and likely represents an Asgard- specific innovation. Moreover, we show that Mg{superscript 2} ions influence Asgard chromatin conformation, suggesting a regulatory role. Overall, our study provides the first structure-based model of Asgard chromatin organization, expanding our understanding of chromatin architecture in evolutionary context.

Published in Molecular Cell (predicted rank #4) · training set

Matching journals

The top 2 journals account for 50% of the predicted probability mass.

1
Nature Communications
○ 5641 papers in training set
Top 0.7%
39.6%
Similar papers in this journal
2
Nature Structural & Molecular Biology
236 papers in training set
Top 0.3%
12.0%
50% of probability mass above
3
Science Advances
● 1243 papers in training set
Top 3%
6.7%
Similar papers in this journal
Molecular Cell · published here
○ 350 papers in training set
Top 1%
6.3%
Similar papers in this journal
5
Proceedings of the National Academy of Sciences
● 2444 papers in training set
Top 13%
4.0%
6
Nucleic Acids Research
◐ 1281 papers in training set
Top 5%
4.0%
Similar papers in this journal
7
eLife
● 5828 papers in training set
Top 33%
3.4%
8
Cell
○ 431 papers in training set
Top 3%
3.3%
9
Structure
○ 193 papers in training set
Top 0.9%
2.8%
10
Communications Biology
○ 993 papers in training set
Top 12%
1.9%
11
Nature
○ 645 papers in training set
Top 7%
1.7%
12
Science
● 477 papers in training set
Top 7%
1.1%
13
Nature Chemistry
○ 42 papers in training set
Top 0.8%
1.0%
14
Cell Reports
○ 1498 papers in training set
Top 25%
1.0%
15
Scientific Reports
○ 3612 papers in training set
Top 76%
0.6%
16
Journal of the American Chemical Society
● 217 papers in training set
Top 3%
0.6%

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.