2nqb

Drosophila Nucleosome Structure

Method: X-RAY DIFFRACTION

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

Histone H3

Drosophila melanogaster

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	alpha-satellite DNA × 2 Histone H4 × 2 （P84040） Histone H2A × 2 （P84051） Histone H2B × 2 （P02283） water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H3_DROME
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain A； PDBConstruct 1–135； UniProt 1–135 Author chain E； PDBConstruct 1–135； UniProt 1–135

Histone H4

Drosophila melanogaster

UniProt P84040

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	alpha-satellite DNA × 2 Histone H3 × 2 （P02299） Histone H2A × 2 （P84051） Histone H2B × 2 （P02283） water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H4_DROME
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain B； PDBConstruct 2–103； UniProt 1–102 Author chain F； PDBConstruct 2–103； UniProt 1–102

Histone H2A

Drosophila melanogaster

UniProt P84051

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	alpha-satellite DNA × 2 Histone H3 × 2 （P02299） Histone H4 × 2 （P84040） Histone H2B × 2 （P02283） water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H2A_DROME
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain C； PDBConstruct 1–123； UniProt 1–123 Author chain G； PDBConstruct 1–123； UniProt 1–123

Histone H2B

Drosophila melanogaster

UniProt P02283

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	alpha-satellite DNA × 2 Histone H3 × 2 （P02299） Histone H4 × 2 （P84040） Histone H2A × 2 （P84051） water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H2B_DROME
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain D； PDBConstruct 1–123； UniProt 1–123 Author chain H； PDBConstruct 1–123； UniProt 1–123

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	2nqb
Deposition date deposition_date	2006-10-30
Structure title title	Drosophila Nucleosome Structure
Keywords keywords	Nucleosome, NCP, chromatin, histone, 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.

2nqb__assembly_1__model_1

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

Download this curve (.dat)

2nqb__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2nqb__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	39.97 Å
Rg (electron density)	37.22 Å
Total Rg	37.94 Å
Atom count	12030
Residues	1054
Excluded volume	195880 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2nqb__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	alpha-satellite DNA
Molecular weight formula_weight	45054.8 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	I,J
Atom count atom_count	12294

ATCAATATCCACCTGCAGATTCTACCAAAAGTGTATTTGGAAACTGCTCCATCAAAAGGCATGTTCAGCGGAATTCCGCTGAACATGCCTTTTGATGGAGCAGTTTCCAAATACACTTTTGGTAGAATCTGCAGGTGGATATTGAT

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	Histone H3
Molecular weight formula_weight	15289.9 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,E

ARTKQTARKSTGGKAPRKQLATKAARKSAPATGGVKKPHRYRPGTVALREIRRYQKSTELLIRKLPFQRLVREIAQDFKTDLRFQSSAVMALQEASEAYLVGLFEDTNLCAIHAKRVTIMPKDIQLARRIRGERA

Source Source

Source organism organism	Drosophila melanogaster
Common name common_name	fruit fly
NCBI taxonomy ID ncbi_taxonomy_id	7227
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 polymer

Description description	Histone H4
Molecular weight formula_weight	11390.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

ITGRGKGGKGLGKGGAKRHRKVLRDNIQGITKPAIRRLARRGGVKRISGLIYEETRGVLKVFLENVIRDAVTYTEHAKRKTVTAMDVVYALKRQGRTLYGFGG

Source Source

Source organism organism	Drosophila melanogaster
Common name common_name	fruit fly
NCBI taxonomy ID ncbi_taxonomy_id	7227
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 polymer

Description description	Histone H2A
Molecular weight formula_weight	13257.5 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

SGRGKGGKVKGKAKSRSNRAGLQFPVGRIHRLLRKGNYAERVGAGAPVYLAAVMEYLAAEVLELAGNAARDNKKTRIIPRHLQLAIRNDEELNKLLSGVTIAQGGVLPNIQAVLLPKKTEKKA

Source Source

Source organism organism	Drosophila melanogaster
Common name common_name	fruit fly
NCBI taxonomy ID ncbi_taxonomy_id	7227
Host organism host_organism	Escherichia coli

Entity 5 Entity 5 polymer

Description description	Histone H2B
Molecular weight formula_weight	13681.0 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

IPPKTSGKAAKKAGKAQKNITKTDKKKKRKRKESYAIYIYTVLKQVHPDTGISSKAMSIMNSFVNDIFERIAAEASRLAHYNKRSTITSREIQTAVRLLLPGELAKHAVSEGTKAVTKYTSSK

Source Source

Source organism organism	Drosophila melanogaster
Common name common_name	fruit fly
NCBI taxonomy ID ncbi_taxonomy_id	7227
Host organism host_organism	Escherichia coli

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	264

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d2nqba_
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	d2nqbb_
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	d2nqbc_
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	d2nqbd_
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	d2nqbe_
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	d2nqbf_
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	d2nqbg_
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	d2nqbh_
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	2nqbA00
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	2nqbB00
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	2nqbC00
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	2nqbD00
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	2nqbE00
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	2nqbF00
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	2nqbG00
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	2nqbH00
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	106.143 Å
Unit-cell length b length_b	109.581 Å
Unit-cell length c length_c	182.045 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	2.300 Å
Low-resolution limit resolution_low	99.000 Å
R factor r_factor	—
R_work r_work	0.2233
R_free r_free	0.2540

Drosophila Nucleosome Structure

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

Histone H3

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

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 H2B

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

2nqb__assembly_1__model_1

2nqb__assembly_1__model_1 | I(q)

2nqb__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

Source Source

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)