EMD-2601
Cryo-EM study of the chromatin fiber reveals a double helix twisted by tetra-nucleosomal units
EMD-2601
Single-particle11.0 Å
Deposition: 05/03/2014Map released: 07/05/2014
Last modified: 07/05/2014
Sample Organism:
Xenopus laevis,
Homo sapiens,
unidentified
Sample: In vitro reconstituted 12x187 bp chromatin
Deposition Authors: Song F, Chen P
,
Sun D ,
Wang M,
Dong L,
Liang D ,
Xu RM,
Zhu P,
Li G
Sample: In vitro reconstituted 12x187 bp chromatin
Deposition Authors: Song F, Chen P
,
Sun D ,
Wang M,
Dong L,
Liang D ,
Xu RM,
Zhu P,
Li G
Cryo-EM study of the chromatin fiber reveals a double helix twisted by tetranucleosomal units
Song F,
Chen P ,
Sun D ,
Wang M,
Dong L,
Liang D ,
Xu RM,
Zhu P,
Li G
(2014) Science , 344 , 376 - 380
,
Sun D ,
Wang M,
Dong L,
Liang D ,
Xu RM,
Zhu P,
Li G
(2014) Science , 344 , 376 - 380
Abstract:
The hierarchical packaging of eukaryotic chromatin plays a central role in transcriptional regulation and other DNA-related biological processes. Here, we report the 11-angstrom-resolution cryogenic electron microscopy (cryo-EM) structures of 30-nanometer chromatin fibers reconstituted in the presence of linker histone H1 and with different nucleosome repeat lengths. The structures show a histone H1-dependent left-handed twist of the repeating tetranucleosomal structural units, within which the four nucleosomes zigzag back and forth with a straight linker DNA. The asymmetric binding and the location of histone H1 in chromatin play a role in the formation of the 30-nanometer fiber. Our results provide mechanistic insights into how nucleosomes compact into higher-order chromatin fibers.
The hierarchical packaging of eukaryotic chromatin plays a central role in transcriptional regulation and other DNA-related biological processes. Here, we report the 11-angstrom-resolution cryogenic electron microscopy (cryo-EM) structures of 30-nanometer chromatin fibers reconstituted in the presence of linker histone H1 and with different nucleosome repeat lengths. The structures show a histone H1-dependent left-handed twist of the repeating tetranucleosomal structural units, within which the four nucleosomes zigzag back and forth with a straight linker DNA. The asymmetric binding and the location of histone H1 in chromatin play a role in the formation of the 30-nanometer fiber. Our results provide mechanistic insights into how nucleosomes compact into higher-order chromatin fibers.