SAXSdb — 1mk2

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

SMAD 3

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	Madh-interacting protein × 2 （O95405） ACETIC ACID × 8	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Madh-interacting protein × 1 （O95405） ACETIC ACID × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SMAD3_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–206； UniProt 220–425

Madh-interacting protein

Homo sapiens

UniProt O95405

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	SMAD 3 × 2 （P84022） ACETIC ACID × 8	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	SMAD 3 × 1 （P84022） ACETIC ACID × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	ZFYV9_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–38； UniProt 773–810

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	1mk2
Deposition date deposition_date	2002-08-28
Structure title title	SMAD3 SBD complex
Keywords keywords	SMAD3, SBD, SARA, 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.

1mk2__assembly_1__model_1

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

Download this curve (.dat)

1mk2__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1mk2__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	24.72 Å
Rg (electron density)	23.77 Å
Total Rg	24.63 Å
Atom count	3696
Residues	470
Excluded volume	65341 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1mk2__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1mk2__assembly_2__model_1`	dimeric （2）	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	SMAD 3
Molecular weight formula_weight	23227.4 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	1848

DLQPVTYCEPAFWCSISYYELNQRVGETFHASQPSMTVDGFTDPSNSERFCLGLLSNVNRNAAVELTRRHIGRGVRLYYIGGEVFAECLSDSAIFVQSPNCNQRYGWHPATVCKIPPGCNLKIFNNQEFAALLAQSVNQGFEAVYQLTRMCTIRMSFVKGWGAEYRRQTVTSTPCWIELHLNGPLQWLDKVLTQMGSPSIRCSSVS

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 polymer

Description description	Madh-interacting protein
Molecular weight formula_weight	3818.2 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

SPNPNNPAEYCSTIPPLQQAQASGALSSPPPTVMVPVG

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 3 Entity 3 non-polymer

Description description	ACETIC ACID
Molecular weight formula_weight	60.1 kDa
Source method src_method	syn
Copy count entity_count	4

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6. Fold Classification (SCOP + CATH) 3 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1mk2a_
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	d1mk2b_
Class class	j — Peptides
Fold Fold fold	j.64 — Smad-binding domain of Sara
Superfamily Superfamily superfamily	j.64.1 — Smad-binding domain of Sara
Family Family family	j.64.1.1 — Smad-binding domain of Sara

CATH v4.4 (1 domains)

Domain ID domain_id	1mk2A00
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	49.995 Å
Unit-cell length b length_b	71.716 Å
Unit-cell length c length_c	86.886 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	4

Space group space_group	P 21 21 2
Space-group number int_tables_number	18
Crystal system crystal_system	—

Resolution resolution	2.740 Å
Low-resolution limit resolution_low	43.440 Å
R factor r_factor	0.2270
R_work r_work	0.2270
R_free r_free	0.2710

SMAD3 SBD complex

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

SMAD 3

State in the Current Structure

Other States of the Same Protein in the Database

Madh-interacting protein

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

1mk2__assembly_1__model_1

1mk2__assembly_1__model_1 | I(q)

1mk2__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 3 domains

SCOP 2.08 (2 domains)

CATH v4.4 (1 domains)

7. Citations (1)

SMAD3 SBD complex

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

SMAD 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

Madh-interacting protein

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

1mk2__assembly_1__model_1

1mk2__assembly_1__model_1 | I(q)

1mk2__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 3 domains

SCOP 2.08 (2 domains)

CATH v4.4 (1 domains)

7. Citations (1)