SAXSdb — 1khu

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

SMAD1

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 3	water × 3	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 3	water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SMAD1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–218； UniProt 248–465 Author chain B； PDBConstruct 1–218； UniProt 248–465 Author chain C； PDBConstruct 1–218； UniProt 248–465 Author chain D； PDBConstruct 1–218； UniProt 248–465

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	1khu
Deposition date deposition_date	2001-12-01
Structure title title	Smad1 crystal structure reveals the details of BMP signaling pathway
Keywords keywords	beta-strand sandwich, TRANSCRIPTION; TRANSCRIPTION
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.

1khu__assembly_1__model_1

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

Download this curve (.dat)

1khu__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1khu__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	26.11 Å
Rg (electron density)	25.06 Å
Total Rg	25.90 Å
Atom count	4711
Residues	592
Excluded volume	82846 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1khu__assembly_1__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1khu__assembly_2__model_1`	trimeric （3）	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 (2)

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6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1khua_
Class class	b — All beta proteins
Fold Fold fold	b.26 — SMAD/FHA domain
Superfamily Superfamily superfamily	b.26.1 — SMAD/FHA domain
Family Family family	b.26.1.1 — SMAD domain

Domain ID domain_id	d1khub_
Class class	b — All beta proteins
Fold Fold fold	b.26 — SMAD/FHA domain
Superfamily Superfamily superfamily	b.26.1 — SMAD/FHA domain
Family Family family	b.26.1.1 — SMAD domain

Domain ID domain_id	d1khuc_
Class class	b — All beta proteins
Fold Fold fold	b.26 — SMAD/FHA domain
Superfamily Superfamily superfamily	b.26.1 — SMAD/FHA domain
Family Family family	b.26.1.1 — SMAD domain

Domain ID domain_id	d1khud_
Class class	b — All beta proteins
Fold Fold fold	b.26 — SMAD/FHA domain
Superfamily Superfamily superfamily	b.26.1 — SMAD/FHA domain
Family Family family	b.26.1.1 — SMAD domain

CATH v4.4 (4 domains)

Domain ID domain_id	1khuA00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	200 — Tumour Suppressor Smad4
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1khuB00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	200 — Tumour Suppressor Smad4
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1khuC00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	200 — Tumour Suppressor Smad4
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1khuD00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	200 — Tumour Suppressor Smad4
Homologous superfamily homologous superfamily	10 —

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Unit-cell length a length_a	138.129 Å
Unit-cell length b length_b	138.129 Å
Unit-cell length c length_c	199.340 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	36

Space group space_group	H 3
Space-group number int_tables_number	146
Crystal system crystal_system	—

Resolution resolution	2.500 Å
Low-resolution limit resolution_low	38.000 Å
R factor r_factor	—
R_work r_work	0.2390
R_free r_free	0.2740

Description description	SMAD1
Molecular weight formula_weight	24545.6 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	6772

Smad1 crystal structure reveals the details of BMP signaling pathway

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

SMAD1

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

1khu__assembly_1__model_1

1khu__assembly_1__model_1 | I(q)

1khu__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	586

Smad1 crystal structure reveals the details of BMP signaling pathway

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

SMAD1

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

1khu__assembly_1__model_1

1khu__assembly_1__model_1 | I(q)

1khu__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)