3a6n

The nucleosome containing a testis-specific histone variant, human H3T

Method: X-RAY DIFFRACTION

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

Histone H3.1t

Homo sapiens

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 （P62805） Histone H2A type 1-B/E × 2 （P04908） Histone H2B type 1-J × 2 （P06899） 146-MER DNA × 2 CHLORIDE ION × 4 MANGANESE (II) ION × 8 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H31T_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 4–139； UniProt 1–136 Author chain E； PDBConstruct 4–139； UniProt 1–136

Histone H4

Homo sapiens

UniProt P62805

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 H3.1t × 2 （Q16695） Histone H2A type 1-B/E × 2 （P04908） Histone H2B type 1-J × 2 （P06899） 146-MER DNA × 2 CHLORIDE ION × 4 MANGANESE (II) ION × 8 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H4_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 4–106； UniProt 1–103 Author chain F； PDBConstruct 4–106； UniProt 1–103

Histone H2A type 1-B/E

Homo sapiens

UniProt P04908

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 H3.1t × 2 （Q16695） Histone H4 × 2 （P62805） Histone H2B type 1-J × 2 （P06899） 146-MER DNA × 2 CHLORIDE ION × 4 MANGANESE (II) ION × 8 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H2A1B_HUMAN
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain C； PDBConstruct 4–133； UniProt 1–130 Author chain G； PDBConstruct 4–133； UniProt 1–130

Histone H2B type 1-J

Homo sapiens

UniProt P06899

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 H3.1t × 2 （Q16695） Histone H4 × 2 （P62805） Histone H2A type 1-B/E × 2 （P04908） 146-MER DNA × 2 CHLORIDE ION × 4 MANGANESE (II) ION × 8 water × 10	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H2B1J_HUMAN
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain D； PDBConstruct 4–129； UniProt 1–126 Author chain H； PDBConstruct 4–129； UniProt 1–126

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	3a6n
Deposition date deposition_date	2009-09-04
Structure title title	The nucleosome containing a testis-specific histone variant, human H3T
Keywords keywords	;histone-fold, DNA-binding protein, Chromosomal protein, Citrullination, DNA-binding, Methylation, Nucleosome core, Nucleus, Phosphoprotein, Isopeptide bond, Antibiotic, Antimicrobial, 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.

3a6n__assembly_1__model_1

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

Download this curve (.dat)

3a6n__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3a6n__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	39.58 Å
Rg (electron density)	36.84 Å
Total Rg	37.56 Å
Atom count	11962
Residues	1046
Excluded volume	195030 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3a6n__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 (8)

Entity 1 Entity 1 polymer

Description description	Histone H3.1t
Molecular weight formula_weight	15823.6 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	12062

GSHMARTKQTARKSTGGKAPRKQLATKVARKSAPATGGVKKPHRYRPGTVALREIRRYQKSTELLIRKLPFQRLMREIAQDFKTDLRFQSSAVMALQEACESYLVGLFEDTNLCVIHAKRVTIMPKDIQLARRIRGERA

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 BL21(DE3)

Entity 2 Entity 2 polymer

Description description	Histone H4
Molecular weight formula_weight	11676.7 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

GSHMSGRGKGGKGLGKGGAKRHRKVLRDNIQGITKPAIRRLARRGGVKRISGLIYEETRGVLKVFLENVIRDAVTYTEHAKRKTVTAMDVVYALKRQGRTLYGFGG

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 3 Entity 3 polymer

Description description	Histone H2A type 1-B/E
Molecular weight formula_weight	14447.8 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

GSHMSGRGKQGGKARAKAKTRSSRAGLQFPVGRVHRLLRKGNYSERVGAGAPVYLAAVLEYLTAEILELAGNAARDNKKTRIIPRHLQLAIRNDEELNKLLGRVTIAQGGVLPNIQAVLLPKKTESHHKAKGK

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 BL21(DE3)

Entity 4 Entity 4 polymer

Description description	Histone H2B type 1-J
Molecular weight formula_weight	14217.5 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

GSHMPEPAKSAPAPKKGSKKAVTKAQKKDGKKRKRSRKESYSIYVYKVLKQVHPDTGISSKAMGIMNSFVNDIFERIAGEASRLAHYNKRSTITSREIQTAVRLLLPGELAKHAVSEGTKAVTKYTSAK

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 BL21(DE3)

Entity 5 Entity 5 polymer

Description description	146-MER DNA
Molecular weight formula_weight	45053.9 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	I,J

ATCAATATCCACCTGCAGATTCTACCAAAAGTGTATTTGGAAACTGCTCCATCAAAAGGCATGTTCAGCTGAATTCAGCTGAACATGCCTTTTGATGGAGCAGTTTCCAAATACACTTTTGGTAGAATCTGCAGGTGGATATTGAT

Entity 6 Entity 6 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 7 Entity 7 non-polymer

Description description	MANGANESE (II) ION
Molecular weight formula_weight	54.9 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 8 Entity 8 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	100

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d3a6na_
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	d3a6nb_
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	d3a6nc_
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	d3a6nd_
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	d3a6ne_
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	d3a6nf_
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	d3a6ng_
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	d3a6nh_
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	3a6nA00
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	3a6nB00
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	3a6nC00
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	3a6nD00
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	3a6nE00
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	3a6nF00
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	3a6nG00
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	3a6nH00
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	105.476 Å
Unit-cell length b length_b	109.521 Å
Unit-cell length c length_c	181.052 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	2.700 Å
Low-resolution limit resolution_low	50.000 Å
R factor r_factor	0.2280
R_work r_work	0.2280
R_free r_free	0.2640

The nucleosome containing a testis-specific histone variant, human H3T

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

Histone H3.1t

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-B/E

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 type 1-J

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

3a6n__assembly_1__model_1

3a6n__assembly_1__model_1 | I(q)

3a6n__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 (8)

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 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)