Structural insights into the histone H1-nucleosome complex.
Linker H1 histones facilitate formation of higher-order chromatin structures and play important roles in various cell functions. Despite several decades of effort, the structural basis of how H1 interacts with the nucleosome remains elusive. Here, we investigated Drosophila H1 in complex with the nucleosome, using solution nuclear magnetic resonance spectroscopy and other biophysical methods. We found that the globular domain of H1 bridges the nucleosome core and one 10-base pair linker DNA asymmetrically, with its α3 helix facing the nucleosomal DNA near the dyad axis. Two short regions in the C-terminal tail of H1 and the C-terminal tail of one of the two H2A histones are also involved in the formation of the H1-nucleosome complex. Our results lead to a residue-specific structural model for the globular domain of the Drosophila H1 in complex with the nucleosome, which is different from all previous experiment-based models and has implications for chromatin dynamics in vivo.
Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Bing-Rui
BR
Zhou
Hanqiao
H
Feng
Hidenori
H
Kato
Liang
L
Dai
Yuedong
Y
Yang
Yaoqi
Y
Zhou
Yawen
Y
Bai
D000595:Amino Acid Sequence; D002151:Calorimetry; D006657:Histones / Q000737:chemistry* / Q000235:genetics; D046911:Macromolecular Substances / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009707:Nucleosomes / Q000737:chemistry*; D011485:Protein Binding
D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes