SAXSdb — 3u1a

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

smooth muscle tropomyosin alpha

Gallus gallus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	water × 2	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 4	water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	P04268
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 4–84； UniProt 1–81 Author chain B； PDBConstruct 4–84； UniProt 1–81 Author chain C； PDBConstruct 4–84； UniProt 1–81 Author chain D； PDBConstruct 4–84； UniProt 1–81

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	3u1a
Deposition date deposition_date	2011-09-29
Structure title title	N-terminal 81-aa fragment of smooth muscle tropomyosin alpha
Keywords keywords	Muscle contraction, Actin, CONTRACTILE PROTEIN; CONTRACTILE 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.

3u1a__assembly_1__model_1

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

Download this curve (.dat)

3u1a__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3u1a__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	32.90 Å
Rg (electron density)	35.42 Å
Total Rg	35.15 Å
Atom count	1326
Residues	166
Excluded volume	23343 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3u1a__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3u1a__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3u1a__assembly_3__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 (2)

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d3u1aa1
Class class	h — Coiled coil proteins
Fold Fold fold	h.1 — Parallel coiled-coil
Superfamily Superfamily superfamily	h.1.5 — Tropomyosin
Family Family family	h.1.5.0 — automated matches

Domain ID domain_id	d3u1aa2
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	d3u1ab1
Class class	h — Coiled coil proteins
Fold Fold fold	h.1 — Parallel coiled-coil
Superfamily Superfamily superfamily	h.1.5 — Tropomyosin
Family Family family	h.1.5.0 — automated matches

Domain ID domain_id	d3u1ab2
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	d3u1ac1
Class class	h — Coiled coil proteins
Fold Fold fold	h.1 — Parallel coiled-coil
Superfamily Superfamily superfamily	h.1.5 — Tropomyosin
Family Family family	h.1.5.0 — automated matches

Domain ID domain_id	d3u1ac2
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	d3u1ad1
Class class	h — Coiled coil proteins
Fold Fold fold	h.1 — Parallel coiled-coil
Superfamily Superfamily superfamily	h.1.5 — Tropomyosin
Family Family family	h.1.5.0 — automated matches

Domain ID domain_id	d3u1ad2
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

CATH v4.4 (4 domains)

Domain ID domain_id	3u1aA00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	340 —

Domain ID domain_id	3u1aB00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	340 —

Domain ID domain_id	3u1aC00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	340 —

Domain ID domain_id	3u1aD00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	340 —

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Unit-cell length a length_a	58.768 Å
Unit-cell length b length_b	63.181 Å
Unit-cell length c length_c	101.299 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	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	39.519 Å
R factor r_factor	0.2245
R_work r_work	0.2223
R_free r_free	0.2652

Description description	smooth muscle tropomyosin alpha
Molecular weight formula_weight	9610.8 kDa
Source method src_method	man
Copy count entity_count	4

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	2878

N-terminal 81-aa fragment of smooth muscle tropomyosin alpha

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

smooth muscle tropomyosin alpha

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

3u1a__assembly_1__model_1

3u1a__assembly_1__model_1 | I(q)

3u1a__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

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (8 domains)

CATH v4.4 (4 domains)

7. Citations (1)

Source organism organism	Gallus gallus
Common name common_name	bantam,chickens
NCBI taxonomy ID ncbi_taxonomy_id	9031
Host organism host_organism	Escherichia coli

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	216

N-terminal 81-aa fragment of smooth muscle tropomyosin alpha

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

smooth muscle tropomyosin alpha

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

3u1a__assembly_1__model_1

3u1a__assembly_1__model_1 | I(q)

3u1a__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

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (8 domains)

CATH v4.4 (4 domains)

7. Citations (1)