8COM image
Entry Detail
PDB ID:
8COM
EMDB ID:
Title:
Structure of the Nucleosome Core Particle from Trypanosoma brucei
Biological Source:
PDB Version:
Deposition Date:
2023-02-28
Release Date:
2023-07-12
Method Details:
Experimental Method:
Resolution:
3.30 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Histone H3, putative
Chain IDs:A, E
Chain Length:132
Number of Molecules:2
Biological Source:Trypanosoma brucei brucei TREU927
Polymer Type:polypeptide(L)
Description:Histone H4
Chain IDs:B, F
Chain Length:99
Number of Molecules:2
Biological Source:Trypanosoma brucei brucei TREU927
Polymer Type:polypeptide(L)
Description:Histone H2A
Chain IDs:C, G
Chain Length:133
Number of Molecules:2
Biological Source:Trypanosoma brucei brucei TREU927
Polymer Type:polypeptide(L)
Description:Histone H2B
Chain IDs:D, H
Chain Length:111
Number of Molecules:2
Biological Source:Trypanosoma brucei brucei TREU927
Polymer Type:polydeoxyribonucleotide
Description:Widom 601 145 bp DNA (127-mer ordered and built)
Chain IDs:I
Chain Length:145
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Description:Widom 601 145 bp DNA (127-mer ordered and built)
Chain IDs:J
Chain Length:145
Number of Molecules:1
Biological Source:synthetic construct
Ligand Molecules
Primary Citation
Histone divergence in trypanosomes results in unique alterations to nucleosome structure.
Nucleic Acids Res. 51 7882 7899 (2023)
PMID: 37427792 DOI: 10.1093/nar/gkad577

Abstact

Eukaryotes have a multitude of diverse mechanisms for organising and using their genomes, but the histones that make up chromatin are highly conserved. Unusually, histones from kinetoplastids are highly divergent. The structural and functional consequences of this variation are unknown. Here, we have biochemically and structurally characterised nucleosome core particles (NCPs) from the kinetoplastid parasite Trypanosoma brucei. A structure of the T. brucei NCP reveals that global histone architecture is conserved, but specific sequence alterations lead to distinct DNA and protein interaction interfaces. The T. brucei NCP is unstable and has weakened overall DNA binding. However, dramatic changes at the H2A-H2B interface introduce local reinforcement of DNA contacts. The T. brucei acidic patch has altered topology and is refractory to known binders, indicating that the nature of chromatin interactions in T. brucei may be unique. Overall, our results provide a detailed molecular basis for understanding evolutionary divergence in chromatin structure.

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Primary Citation of related structures