SAXSdb — 2ra4

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

Small-inducible cytokine A13

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 6 trifluoroacetic acid × 1 water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 8	SULFATE ION × 24 trifluoroacetic acid × 4 water × 8	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 4	SULFATE ION × 12 water × 4	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 4	SULFATE ION × 12 trifluoroacetic acid × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CCL13_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–76； UniProt 24–98 Author chain B； PDBConstruct 2–76； UniProt 24–98

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	2ra4
Deposition date deposition_date	2007-09-14
Structure title title	Crystal Structure of Human Monocyte Chemoattractant Protein 4 (MCP-4/CCL13)
Keywords keywords	CCL13, MCP-4, CC chemokine family, chemotaxis, monocytes, Cytokine, Inflammatory response, Pyrrolidone carboxylic acid, Secreted; CYTOKINE
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.

2ra4__assembly_3__model_1

Assembly 3 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

2ra4__assembly_3__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2ra4__assembly_3__model_1 | P(r) · Pending

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

Rg（Guinier）	21.60 Å
Rg (electron density)	20.65 Å
Total Rg	21.46 Å
Atom count	2136
Residues	260
Excluded volume	38391 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2ra4__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2ra4__assembly_2__model_1`	octameric （8）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`2ra4__assembly_3__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`2ra4__assembly_4__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	Small-inducible cytokine A13
Molecular weight formula_weight	8747.4 kDa
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	1208

MQPDALNVPSTCCFTFSSKKISLQRLKSYVITTSRCPQKAVIFRTKLGKEICADPKEKWVQNYMKHLGRKAHTLKT

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 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 3 Entity 3 non-polymer

Description description	trifluoroacetic acid
Molecular weight formula_weight	114.0 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	72

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d2ra4a_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.9 — IL8-like
Superfamily Superfamily superfamily	d.9.1 — Interleukin 8-like chemokines
Family Family family	d.9.1.1 — Interleukin 8-like chemokines

Domain ID domain_id	d2ra4b_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.9 — IL8-like
Superfamily Superfamily superfamily	d.9.1 — Interleukin 8-like chemokines
Family Family family	d.9.1.1 — Interleukin 8-like chemokines

CATH v4.4 (2 domains)

Domain ID domain_id	2ra4A00
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	2ra4B00
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	74.673 Å
Unit-cell length b length_b	74.673 Å
Unit-cell length c length_c	51.650 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	16

Space group space_group	I 4
Space-group number int_tables_number	79
Crystal system crystal_system	—

Resolution resolution	1.700 Å
Low-resolution limit resolution_low	30.000 Å
R factor r_factor	0.1815
R_work r_work	0.1797
R_free r_free	0.2158

Crystal Structure of Human Monocyte Chemoattractant Protein 4 (MCP-4/CCL13)

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

Small-inducible cytokine A13

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

2ra4__assembly_3__model_1

2ra4__assembly_3__model_1 | I(q)

2ra4__assembly_3__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

Crystal Structure of Human Monocyte Chemoattractant Protein 4 (MCP-4/CCL13)

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

Small-inducible cytokine A13

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

2ra4__assembly_3__model_1

2ra4__assembly_3__model_1 | I(q)

2ra4__assembly_3__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)