3c1b

The effect of H3 K79 dimethylation and H4 K20 trimethylation on nucleosome and chromatin structure

Method: X-RAY DIFFRACTION

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Histone H3-like

Xenopus laevis

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 8 DNA 2	Histone H4 × 2 （P62799） Histone H2A type 1 × 2 （P06897） Histone 2, H2bf × 2 （Q28D68） Palindromic 146bp Human Alpha satellite DNA × 2 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H3L_XENLA
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–135； UniProt 2–136 Author chain E； PDBConstruct 1–135； UniProt 2–136

Histone H4

Xenopus laevis

UniProt P62799

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 8 DNA 2	Histone H3-like × 2 （P02302） Histone H2A type 1 × 2 （P06897） Histone 2, H2bf × 2 （Q28D68） Palindromic 146bp Human Alpha satellite DNA × 2 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H4_XENLA
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–102； UniProt 2–103 Author chain F； PDBConstruct 1–102； UniProt 2–103

Histone H2A type 1

Xenopus laevis

UniProt P06897

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 8 DNA 2	Histone H3-like × 2 （P02302） Histone H4 × 2 （P62799） Histone 2, H2bf × 2 （Q28D68） Palindromic 146bp Human Alpha satellite DNA × 2 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H2A1_XENLA
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain C； PDBConstruct 1–129； UniProt 2–130 Author chain G； PDBConstruct 1–129； UniProt 2–130

Histone 2, H2bf

Xenopus (Silurana) tropicalis

UniProt Q28D68

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Heteromer	Protein 8 DNA 2	Histone H3-like × 2 （P02302） Histone H4 × 2 （P62799） Histone H2A type 1 × 2 （P06897） Palindromic 146bp Human Alpha satellite DNA × 2 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q28D68_XENTR
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain D； PDBConstruct 1–125； UniProt 2–126 Author chain H； PDBConstruct 1–125； UniProt 2–126

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	3c1b
Deposition date deposition_date	2008-01-22
Structure title title	The effect of H3 K79 dimethylation and H4 K20 trimethylation on nucleosome and chromatin structure
Keywords keywords	;Nucleosome, Dimethylated histone, trimethylated histone, methylation, nucleosomal surface, histone modification, nucleosomal array, chromatin, Acetylation, Chromosomal protein, DNA-binding, Nucleosome core, Nucleus, Phosphoprotein, Ubl conjugation, Structural PROTEIN-DNA COMPLEX ;; Structural PROTEIN/DNA
Experimental Method method	X-RAY DIFFRACTION

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

3c1b__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

3c1b__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3c1b__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	39.88 Å
Rg (electron density)	37.16 Å
Total Rg	37.88 Å
Atom count	12041
Residues	1053
Excluded volume	196150 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3c1b__assembly_1__model_1`	decameric （10）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (6)

Entity 1 Entity 1 polymer

Description description	Histone H3-like
Molecular weight formula_weight	15303.9 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,E
Atom count atom_count	12828

ARTKQTARKSTGGKAPRKQLATKAARKSAPATGGVKKPHRYRPGTVALREIRRYQKSTELLIRKLPFQRLVREIAQDFKTDLRFQSSAVMALQEASEAYLVALFEDTNLCAIHAKRVTIMPKDIQLARRIRGERA

Source Source

Source organism organism	Xenopus laevis
Common name common_name	clawed frog,common platanna,platanna
NCBI taxonomy ID ncbi_taxonomy_id	8355
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	Histone H4
Molecular weight formula_weight	11323.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,F

SGRGKGGKGLGKGGAKRHRKVLRDNIQGITKPAIRRLARRGGVKRISGLIYEETRGVLKVFLENVIRDAVTYTEHAKRKTVTAMDVVYALKRQGRTLYGFGG

Source Source

Source organism organism	Xenopus laevis
Common name common_name	clawed frog,common platanna,platanna
NCBI taxonomy ID ncbi_taxonomy_id	8355
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 polymer

Description description	Histone H2A type 1
Molecular weight formula_weight	14008.3 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C,G

SGRGKQGGKTRAKAKTRSSRAGLQFPVGRVHRLLRKGNYAERVGAGAPVYLAAVLEYLTAEILELAGNAARDNKKTRIIPRHLQLAVRNDEELNKLLGRVTIAQGGVLPNIQSVLLPKKTESSKSTKSK

Source Source

Source organism organism	Xenopus laevis
Common name common_name	clawed frog,common platanna,platanna
NCBI taxonomy ID ncbi_taxonomy_id	8355
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 polymer

Description description	Histone 2, H2bf
Molecular weight formula_weight	13808.0 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D,H

PDPAKSAPAAKKGSKKAVTKTQKKDGKKRRKTRKESYAIYVYKVLKQVHPDTGISSKAMSIMNSFVNDVFERIAGEASRLAHYNKRSTITSREIQTAVRLLLPGELAKHAVSEGTKAVTKYTSAK

Source Source

Source organism organism	Xenopus (Silurana) tropicalis
Common name common_name	Western clawed frog
NCBI taxonomy ID ncbi_taxonomy_id	8364
Host organism host_organism	Escherichia coli

Entity 5 Entity 5 polymer

Description description	Palindromic 146bp Human Alpha satellite DNA
Molecular weight formula_weight	45054.8 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	I,J

ATCAATATCCACCTGCAGATTCTACCAAAAGTGTATTTGGAAACTGCTCCATCAAAAGGCATGTTCAGCGGAATTCCGCTGAACATGCCTTTTGATGGAGCAGTTTCCAAATACACTTTTGGTAGAATCTGCAGGTGGATATTGAT

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	787

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d3c1ba_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bb_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bc_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bd_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1be_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bf_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bg_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

Domain ID domain_id	d3c1bh_
Class class	a — All alpha proteins
Fold Fold fold	a.22 — Histone-fold
Superfamily Superfamily superfamily	a.22.1 — Histone-fold
Family Family family	a.22.1.1 — Nucleosome core histones

CATH v4.4 (8 domains)

Domain ID domain_id	3c1bA00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bB00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bC00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bD00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bE00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bF00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bG00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

Domain ID domain_id	3c1bH00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	20 — Histone, subunit A
Homologous superfamily homologous superfamily	10 — Histone, subunit A

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Unit-cell length a length_a	105.670 Å
Unit-cell length b length_b	109.830 Å
Unit-cell length c length_c	181.030 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	2.200 Å
Low-resolution limit resolution_low	43.000 Å
R factor r_factor	—
R_work r_work	0.2400
R_free r_free	0.2700

The effect of H3 K79 dimethylation and H4 K20 trimethylation on nucleosome and chromatin structure

1. Protein Identity and Related Structures Protein Identity & Related Structures

Histone H3-like

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Histone H4

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Histone H2A type 1

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Histone 2, H2bf

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

3c1b__assembly_1__model_1

3c1b__assembly_1__model_1 | I(q)

3c1b__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 polymer

Polymer Polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)