SAXSdb — 4z2m

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

FACT complex subunit SPT16

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 5	Histone H3.1 × 2 （P68431） Histone H4 × 2 （P62805）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SP16H_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain B； PDBConstruct 1–287； UniProt 644–930

Histone H3.1

Homo sapiens

UniProt P68431

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 5	FACT complex subunit SPT16 × 1 （Q9Y5B9） Histone H4 × 2 （P62805）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H31_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain G； PDBConstruct 1–102； UniProt 35–136 Author chain I； PDBConstruct 1–102； UniProt 35–136

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 heterocomplex	Heteromer	Protein 5	FACT complex subunit SPT16 × 1 （Q9Y5B9） Histone H3.1 × 2 （P68431）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	H4_HUMAN
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain H； PDBConstruct 1–103； UniProt 1–103 Author chain J； PDBConstruct 1–103； UniProt 1–103

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	4z2m
Deposition date deposition_date	2015-03-30
Structure title title	Crystal structure of human SPT16 Mid-AID/H3-H4 tetramer FACT Histone complex
Keywords keywords	Transcription, Transcription-DNA binding protein complex; Transcription/DNA binding protein
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.

4z2m__assembly_1__model_1

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

Download this curve (.dat)

4z2m__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

4z2m__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	29.05 Å
Rg (electron density)	28.21 Å
Total Rg	29.00 Å
Atom count	4594
Residues	565
Excluded volume	82535 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`4z2m__assembly_1__model_1`	pentameric （5）	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 (3)

Entity 1 Entity 1 polymer

Description description	FACT complex subunit SPT16
Molecular weight formula_weight	33372.2 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B
Atom count atom_count	4594

GIVKQDSLVINLNRSNPKLKDLYIRPNIAQKRMQGSLEAHVNGFRFTSVRGDKVDILYNNIKHALFQPCDGEMIIVLHFHLKNAIMFGKKRHTDVQFYTEVGEITTDLGKHQHMHDRDDLYAEQMEREMRHKLKTAFKNFIEKVEALTKEELEFEVPFRDLGFNGAPYRSTCLLQPTSSALVNATEWPPFVVTLDEVELIHFERVQFHLKNFDMVIVYKDYSKKVTMINAIPVASLDPIKEWLNSCDLKYTEGVQSLNWTKIMKTIVDDPEGFFEQGGWSFLEPEGE

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Baculovirus expression vector pFastBac1-HM

Entity 2 Entity 2 polymer

Description description	Histone H3.1
Molecular weight formula_weight	11919.0 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

GVKKPHRYRPGTVALREIRRYQKSTELLIRKLPFQRLVREIAQDFKTDLRFQSSAVMALQEACEAYLVGLFEDTNLCAIHAKRVTIMPKDIQLARRIRGERA

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Baculovirus expression vector pFastBac1-HM

Entity 3 Entity 3 polymer

Description description	Histone H4
Molecular weight formula_weight	11394.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

MSGRGKGGKGLGKGGAKRHRKVLRDNIQGITKPAIRRLARRGGVKRISGLIYEETRGVLKVFLENVIRDAVTYTEHAKRKTVTAMDVVYALKRQGRTLYGFGG

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Baculovirus expression vector pFastBac1-HM

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6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d4z2mg_
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	d4z2mh_
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	d4z2mi_
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	d4z2mj_
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 (6 domains)

Domain ID domain_id	4z2mB01
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	29 — PH-domain like
Homologous superfamily homologous superfamily	150 —

Domain ID domain_id	4z2mB02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	29 — PH-domain like
Homologous superfamily homologous superfamily	30 — Pleckstrin-homology domain (PH domain)/Phosphotyrosine-binding domain (PTB)

Domain ID domain_id	4z2mG00
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	4z2mH00
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	4z2mI00
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	4z2mJ00
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	65.442 Å
Unit-cell length b length_b	69.784 Å
Unit-cell length c length_c	187.853 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 2 21
Space-group number int_tables_number	18
Crystal system crystal_system	—

Resolution resolution	2.981 Å
Low-resolution limit resolution_low	46.963 Å
R factor r_factor	0.1960
R_work r_work	0.1904
R_free r_free	0.2465

Crystal structure of human SPT16 Mid-AID/H3-H4 tetramer FACT Histone complex

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

FACT complex subunit SPT16

State in the Current Structure

Other States of the Same Protein in the Database

Histone H3.1

State in the Current Structure

Other States of the Same Protein in the Database

Histone H4

State in the Current Structure

Other States of the Same Protein in the Database

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

4z2m__assembly_1__model_1

4z2m__assembly_1__model_1 | I(q)

4z2m__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 (3)

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

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (1)

Crystal structure of human SPT16 Mid-AID/H3-H4 tetramer FACT Histone complex

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

FACT complex subunit SPT16

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 H3.1

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 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

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

4z2m__assembly_1__model_1

4z2m__assembly_1__model_1 | I(q)

4z2m__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 (3)

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

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (1)