SAXSdb — 2b2t

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

Chromodomain-helicase-DNA-binding protein 1

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Histone H3 tail × 1 （P68431） water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CHD1_HUMAN
Isoform	—
PDB entities	1, 2
Chains and sequence ranges	Author chain A； PDBConstruct 10–185； UniProt 268–443 Author chain B； PDBConstruct 10–185； UniProt 268–443 Author chain C； PDBConstruct 10–115； UniProt 268–373

Histone H3 tail

OrganismNot specified

UniProt P68431

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Chromodomain-helicase-DNA-binding protein 1 × 2 （O14646） Chromodomain-helicase-DNA-binding protein 1 × 1 （O14646） water × 4	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	3
Chains and sequence ranges	Author chain D； PDBConstruct 1–19； UniProt 1–19

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	2b2t
Deposition date deposition_date	2005-09-19
Structure title title	Tandem chromodomains of human CHD1 complexed with Histone H3 Tail containing trimethyllysine 4 and phosphothreonine 3
Keywords keywords	;CHD, Chromodomain, three stranded antiparallel Beta sheet, alpha helix linker, histone H3, trimethyllysine, phosphothreonine, PEPTIDE BINDING PROTEIN ;; PEPTIDE 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.

2b2t__assembly_1__model_1

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

Download this curve (.dat)

2b2t__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2b2t__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	25.87 Å
Rg (electron density)	25.19 Å
Total Rg	25.91 Å
Atom count	3610
Residues	431
Excluded volume	63582 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2b2t__assembly_1__model_1`	tetrameric （4）	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 (4)

Entity 1 Entity 1 polymer

Description description	Chromodomain-helicase-DNA-binding protein 1
Molecular weight formula_weight	22362.4 kDa
Mutation mutation	C436M
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	3868

MKKHHHHHHEEEFETIERFMDCRIGRKGATGATTTIYAVEADGDPNAGFEKNKEPGEIQYLIKWKGWSHIHNTWETEETLKQQNVRGMKKLDNYKKKDQETKRWLKNASPEDVEYYNCQQELTDDLHKQYQIVGRIIAHSNQKSAAGYPDYYCKWQGLPYSECSWEDGALISKKFQAMIDEYFSRKK

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	Chromodomain-helicase-DNA-binding protein 1
Molecular weight formula_weight	13835.0 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C

MKKHHHHHHEEEFETIERFMDCRIGRKGATGATTTIYAVEADGDPNAGFEKNKEPGEIQYLIKWKGWSHIHNTWETEETLKQQNVRGMKKLDNYKKKDQETKRWLKNASPEDVEY

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 3 Entity 3 polymer

Description description	Histone H3 tail
Molecular weight formula_weight	2362.6 kDa
Source method src_method	syn
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D

ARTKQTARKSTGGKAPRKQY

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	258

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (7 domains)

Domain ID domain_id	d2b2ta1
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.13 — Chromo domain-like
Family Family family	b.34.13.2 — Chromo domain

Domain ID domain_id	d2b2ta2
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.13 — Chromo domain-like
Family Family family	b.34.13.2 — Chromo domain

Domain ID domain_id	d2b2ta3
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d2b2tb1
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.13 — Chromo domain-like
Family Family family	b.34.13.2 — Chromo domain

Domain ID domain_id	d2b2tb2
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.13 — Chromo domain-like
Family Family family	b.34.13.2 — Chromo domain

Domain ID domain_id	d2b2tb3
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d2b2tc1
Class class	b — All beta proteins
Fold Fold fold	b.34 — SH3-like barrel
Superfamily Superfamily superfamily	b.34.13 — Chromo domain-like
Family Family family	b.34.13.2 — Chromo domain

CATH v4.4 (5 domains)

Domain ID domain_id	2b2tA01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	40 —

Domain ID domain_id	2b2tA02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	40 —

Domain ID domain_id	2b2tB01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	40 —

Domain ID domain_id	2b2tB02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	40 —

Domain ID domain_id	2b2tC00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	40 —

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Unit-cell length a length_a	111.986 Å
Unit-cell length b length_b	54.686 Å
Unit-cell length c length_c	100.989 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	112.15 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	C 1 2 1
Space-group number int_tables_number	5
Crystal system crystal_system	—

Resolution resolution	2.450 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.2180
R_work r_work	0.2180
R_free r_free	0.2660

Tandem chromodomains of human CHD1 complexed with Histone H3 Tail containing trimethyllysine 4 and phosphothreonine 3

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

Chromodomain-helicase-DNA-binding protein 1

State in the Current Structure

Other States of the Same Protein in the Database

Histone H3 tail

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

2b2t__assembly_1__model_1

2b2t__assembly_1__model_1 | I(q)

2b2t__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (4)

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

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (7 domains)

CATH v4.4 (5 domains)

7. Citations (1)

Tandem chromodomains of human CHD1 complexed with Histone H3 Tail containing trimethyllysine 4 and phosphothreonine 3

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

Chromodomain-helicase-DNA-binding protein 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 H3 tail

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

2b2t__assembly_1__model_1

2b2t__assembly_1__model_1 | I(q)

2b2t__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (4)

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

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (7 domains)

CATH v4.4 (5 domains)

7. Citations (1)