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Open data
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Basic information
Entry | Database: PDB / ID: 3c9k | ||||||
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Title | Model of Histone Octamer Tubular Crystals | ||||||
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![]() | DNA BINDING PROTEIN / helix / tubular crystal / Chromosomal protein / Nucleosome core / Nucleus / Phosphoprotein / Methylation | ||||||
Function / homology | ![]() PKMTs methylate histone lysines / HDMs demethylate histones / RMTs methylate histone arginines / SUMOylation of chromatin organization proteins / Condensation of Prophase Chromosomes / Nonhomologous End-Joining (NHEJ) / G2/M DNA damage checkpoint / Processing of DNA double-strand break ends / Interleukin-7 signaling / Chromatin modifying enzymes ...PKMTs methylate histone lysines / HDMs demethylate histones / RMTs methylate histone arginines / SUMOylation of chromatin organization proteins / Condensation of Prophase Chromosomes / Nonhomologous End-Joining (NHEJ) / G2/M DNA damage checkpoint / Processing of DNA double-strand break ends / Interleukin-7 signaling / Chromatin modifying enzymes / Metalloprotease DUBs / Formation of the beta-catenin:TCF transactivating complex / PRC2 methylates histones and DNA / Oxidative Stress Induced Senescence / HDACs deacetylate histones / HATs acetylate histones / Transcriptional regulation by small RNAs / Activated PKN1 stimulates transcription of AR (androgen receptor) regulated genes KLK2 and KLK3 / Recruitment and ATM-mediated phosphorylation of repair and signaling proteins at DNA double strand breaks / Assembly of the ORC complex at the origin of replication / RNA Polymerase I Promoter Opening / RNA Polymerase I Promoter Escape / RUNX1 regulates genes involved in megakaryocyte differentiation and platelet function / Estrogen-dependent gene expression / MLL4 and MLL3 complexes regulate expression of PPARG target genes in adipogenesis and hepatic steatosis / Regulation of endogenous retroelements by KRAB-ZFP proteins / Regulation of endogenous retroelements by the Human Silencing Hub (HUSH) complex / UCH proteinases / B-WICH complex positively regulates rRNA expression / Ub-specific processing proteases / Deposition of new CENPA-containing nucleosomes at the centromere / Factors involved in megakaryocyte development and platelet production / structural constituent of chromatin / nucleosome / heterochromatin formation / nucleosome assembly / protein heterodimerization activity / protein-containing complex binding / DNA binding / nucleoplasm / nucleus Similarity search - Function | ||||||
Biological species | ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / negative staining / cryo EM / Resolution: 20 Å | ||||||
![]() | Frouws, T.D. | ||||||
![]() | ![]() Title: Histone octamer helical tubes suggest that an internucleosomal four-helix bundle stabilizes the chromatin fiber. Authors: Timothy D Frouws / Hugh-G Patterton / Bryan T Sewell / ![]() Abstract: A major question in chromatin involves the exact organization of nucleosomes within the 30-nm chromatin fiber and its structural determinants of assembly. Here we investigate the structure of histone ...A major question in chromatin involves the exact organization of nucleosomes within the 30-nm chromatin fiber and its structural determinants of assembly. Here we investigate the structure of histone octamer helical tubes via the method of iterative helical real-space reconstruction. Accurate placement of the x-ray structure of the histone octamer within the reconstructed density yields a pseudoatomic model for the entire helix, and allows precise identification of molecular interactions between neighboring octamers. One such interaction that would not be obscured by DNA in the nucleosome consists of a twofold symmetric four-helix bundle formed between pairs of H2B-alpha3 and H2B-alphaC helices of neighboring octamers. We believe that this interface can act as an internucleosomal four-helix bundle within the context of the chromatin fiber. The potential relevance of this interface in the folding of the 30-nm chromatin fiber is discussed. | ||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 153 KB | Display | ![]() |
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PDB format | ![]() | 120.8 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 1469MC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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1 | ![]()
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3 | ![]()
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Symmetry | Helical symmetry: (Circular symmetry: 11 / Dyad axis: no / N subunits divisor: 1 / Num. of operations: 88 / Rise per n subunits: 65.12 Å / Rotation per n subunits: -7.56 °) |
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Components
#1: Protein | Mass: 13838.167 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #2: Protein | Mass: 13864.097 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #3: Protein | Mass: 15289.904 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #4: Protein | Mass: 11263.231 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: FILAMENT / 3D reconstruction method: helical reconstruction |
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Sample preparation
Component | Name: Histone Octamer Tubular Crystal / Type: COMPLEX Details: Histone Octamers are assembled into ring with 11-fold rotational symmetry, rings are further stacked via helical symmetry |
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Buffer solution | Name: 100mM Tris-HCl, 2M NaCl, 40% NH2SO4 / pH: 7.4 / Details: 100mM Tris-HCl, 2M NaCl, 40% NH2SO4 |
Specimen | Conc.: 2 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: YES / Vitrification applied: YES |
EM staining | Type: NEGATIVE / Material: Uranyl Acetate |
Specimen support | Details: 300 mesh continous carbon grids |
Vitrification | Details: Negative Stain 0.2% Uranyl Acetate |
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Electron microscopy imaging
Microscopy | Model: ZEISS LEO912 |
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Electron gun | Electron source: TUNGSTEN HAIRPIN / Accelerating voltage: 120 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 50000 X / Nominal defocus max: 800 nm / Nominal defocus min: 1000 nm |
Specimen holder | Temperature: 295 K / Tilt angle max: 0 ° / Tilt angle min: 0 ° |
Image recording | Electron dose: 100 e/Å2 / Film or detector model: KODAK SO-163 FILM |
Radiation | Protocol: SINGLE WAVELENGTH / Monochromatic (M) / Laue (L): M / Scattering type: x-ray |
Radiation wavelength | Relative weight: 1 |
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Processing
EM software | Name: SPIDER / Category: 3D reconstruction | ||||||||||||
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3D reconstruction | Method: Iterative Helical Real Space Reconstruction / Resolution: 20 Å / Num. of particles: 3500 / Nominal pixel size: 4 Å / Actual pixel size: 4 Å Details: 11-fold rotational symmetry imposed during backprojection Symmetry type: HELICAL | ||||||||||||
Atomic model building | Protocol: RIGID BODY FIT / Space: REAL / Target criteria: Cross-correlation and van der Waals energy Details: METHOD--Because of the helical line group, the dyad axis is constrained to lie facing the helical axis and reduces the search to rotations and translations about this dyad REFINEMENT ...Details: METHOD--Because of the helical line group, the dyad axis is constrained to lie facing the helical axis and reduces the search to rotations and translations about this dyad REFINEMENT PROTOCOL--Constrained Rigid Body | ||||||||||||
Atomic model building | PDB-ID: 2HIO Accession code: 2HIO / Source name: PDB / Type: experimental model | ||||||||||||
Refinement step | Cycle: LAST
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