3b4v

X-Ray structure of Activin in complex with FSTL3

Method: X-RAY DIFFRACTION

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

Inhibin beta A chain

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	follistatin-like 3 × 2 （O95633） 1,2-ETHANEDIOL × 2 SULFATE ION × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 water × 4	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	follistatin-like 3 × 2 （O95633） 1,2-ETHANEDIOL × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	INHBA_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–116； UniProt 311–426 Author chain B； PDBConstruct 1–116； UniProt 311–426 Author chain E； PDBConstruct 1–116； UniProt 311–426 Author chain F； PDBConstruct 1–116； UniProt 311–426

follistatin-like 3

Homo sapiens

UniProt O95633

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Inhibin beta A chain × 2 （P08476） 1,2-ETHANEDIOL × 2 SULFATE ION × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 water × 4	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	Inhibin beta A chain × 2 （P08476） 1,2-ETHANEDIOL × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	FSTL3_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 1–237； UniProt 27–263 Author chain D； PDBConstruct 1–237； UniProt 27–263 Author chain G； PDBConstruct 1–237； UniProt 27–263 Author chain H； PDBConstruct 1–237； UniProt 27–263

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	3b4v
Deposition date deposition_date	2007-10-24
Structure title title	X-Ray structure of Activin in complex with FSTL3
Keywords keywords	;Ligand-inhibitor signalling complex, Cleavage on pair of basic residues, Glycoprotein, Growth factor, Hormone, Secreted, Nucleus, Proto-oncogene, HORMONE REGULATOR COMPLEX ;; HORMONE REGULATOR COMPLEX
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.

3b4v__assembly_1__model_1

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

Download this curve (.dat)

3b4v__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3b4v__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	30.25 Å
Rg (electron density)	29.39 Å
Total Rg	30.05 Å
Atom count	4795
Residues	642
Excluded volume	84013 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3b4v__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3b4v__assembly_2__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 (6)

Entity 1 Entity 1 polymer

Description description	Inhibin beta A chain
Molecular weight formula_weight	12991.9 kDa
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,E,F
Atom count atom_count	9726

GLECDGKVNICCKKQFFVSFKDIGWNDWIIAPSGYHANYCEGECPSHIAGTSGSSLSFHSTVINHYRMRGHSPFANLKSCCVPTKLRPMSMLYYDDGQNIIKKDIQNMIVEECGCS

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 2 Entity 2 polymer

Description description	follistatin-like 3
Molecular weight formula_weight	24988.4 kDa
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

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

MGSGNPAPGGVCWLQQGQEATCSLVLQTDVTRAECCASGNIDTAWSNLTHPGNKINLLGFLGLVHCLPCKDSCDGVECGPGKACRMLGGRPRCECAPDCSGLPARLQVCGSDGATYRDECELRAARCRGHPDLSVMYRGRCRKSCEHVVCPRPQSCVVDQTGSAHCVVCRAAPCPVPSSPGQELCGNNNVTYISSCHMRQATCFLGRSIGVRHAGSCAGTPEEPPGGESAEEEENFV

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 3 Entity 3 non-polymer

Description description	1,2-ETHANEDIOL
Molecular weight formula_weight	62.1 kDa
Source method src_method	syn
Copy count entity_count	3

Entity 4 Entity 4 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 5 Entity 5 non-polymer

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	221.2 kDa
Source method src_method	man
Copy count entity_count	2

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	177

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6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d3b4va_
Class class	g — Small proteins
Fold Fold fold	g.17 — Cystine-knot cytokines
Superfamily Superfamily superfamily	g.17.1 — Cystine-knot cytokines
Family Family family	g.17.1.2 — Transforming growth factor (TGF)-beta

Domain ID domain_id	d3b4vb_
Class class	g — Small proteins
Fold Fold fold	g.17 — Cystine-knot cytokines
Superfamily Superfamily superfamily	g.17.1 — Cystine-knot cytokines
Family Family family	g.17.1.2 — Transforming growth factor (TGF)-beta

Domain ID domain_id	d3b4ve_
Class class	g — Small proteins
Fold Fold fold	g.17 — Cystine-knot cytokines
Superfamily Superfamily superfamily	g.17.1 — Cystine-knot cytokines
Family Family family	g.17.1.2 — Transforming growth factor (TGF)-beta

Domain ID domain_id	d3b4vf_
Class class	g — Small proteins
Fold Fold fold	g.17 — Cystine-knot cytokines
Superfamily Superfamily superfamily	g.17.1 — Cystine-knot cytokines
Family Family family	g.17.1.2 — Transforming growth factor (TGF)-beta

CATH v4.4 (16 domains)

Domain ID domain_id	3b4vA00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	90 — Cystine Knot Cytokines, subunit B
Homologous superfamily homologous superfamily	10 — Cystine-knot cytokines

Domain ID domain_id	3b4vB00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	90 — Cystine Knot Cytokines, subunit B
Homologous superfamily homologous superfamily	10 — Cystine-knot cytokines

Domain ID domain_id	3b4vC01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	290 — Extracellular Matrix Fibrillin
Homologous superfamily homologous superfamily	10 — TGF-beta binding (TB) domain

Domain ID domain_id	3b4vC02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vC03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vD01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	290 — Extracellular Matrix Fibrillin
Homologous superfamily homologous superfamily	10 — TGF-beta binding (TB) domain

Domain ID domain_id	3b4vD02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vD03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vE00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	90 — Cystine Knot Cytokines, subunit B
Homologous superfamily homologous superfamily	10 — Cystine-knot cytokines

Domain ID domain_id	3b4vF00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	90 — Cystine Knot Cytokines, subunit B
Homologous superfamily homologous superfamily	10 — Cystine-knot cytokines

Domain ID domain_id	3b4vG01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	290 — Extracellular Matrix Fibrillin
Homologous superfamily homologous superfamily	10 — TGF-beta binding (TB) domain

Domain ID domain_id	3b4vG02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vG03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vH01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	290 — Extracellular Matrix Fibrillin
Homologous superfamily homologous superfamily	10 — TGF-beta binding (TB) domain

Domain ID domain_id	3b4vH02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

Domain ID domain_id	3b4vH03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	60 — Wheat Germ Agglutinin (Isolectin 2); domain 1
Homologous superfamily homologous superfamily	30 —

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Unit-cell length a length_a	63.613 Å
Unit-cell length b length_b	71.384 Å
Unit-cell length c length_c	100.203 Å
Unit-cell angle α angle_alpha	98.55 °
Unit-cell angle β angle_beta	90.64 °
Unit-cell angle γ angle_gamma	90.11 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 1
Space-group number int_tables_number	1
Crystal system crystal_system	—

Resolution resolution	2.480 Å
Low-resolution limit resolution_low	31.780 Å
R factor r_factor	0.2293
R_work r_work	0.2266
R_free r_free	0.2788

X-Ray structure of Activin in complex with FSTL3

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

Inhibin beta A chain

State in the Current Structure

Other States of the Same Protein in the Database

follistatin-like 3

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

3b4v__assembly_1__model_1

3b4v__assembly_1__model_1 | I(q)

3b4v__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 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (4 domains)

CATH v4.4 (16 domains)

7. Citations (1)

X-Ray structure of Activin in complex with FSTL3

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

Inhibin beta A chain

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

follistatin-like 3

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

3b4v__assembly_1__model_1

3b4v__assembly_1__model_1 | I(q)

3b4v__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 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 20 domains

SCOP 2.08 (4 domains)

CATH v4.4 (16 domains)

7. Citations (1)