3t9n

Crystal structure of a membrane protein

Method: X-RAY DIFFRACTION

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

Small-conductance mechanosensitive channel

Thermoanaerobacter tengcongensis

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 7	DODECYL-BETA-D-MALTOSIDE × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q8R6L9_THETN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–282； UniProt 1–282 Author chain B； PDBConstruct 1–282； UniProt 1–282 Author chain C； PDBConstruct 1–282； UniProt 1–282 Author chain D； PDBConstruct 1–282； UniProt 1–282 Author chain E； PDBConstruct 1–282； UniProt 1–282 Author chain F； PDBConstruct 1–282； UniProt 1–282 Author chain G； PDBConstruct 1–282； UniProt 1–282

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	3t9n
Deposition date deposition_date	2011-08-03
Structure title title	Crystal structure of a membrane protein
Keywords keywords	Membrane protein, channel; MEMBRANE 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.

3t9n__assembly_1__model_1

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

Download this curve (.dat)

3t9n__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3t9n__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	40.47 Å
Rg (electron density)	40.43 Å
Total Rg	40.91 Å
Atom count	14789
Residues	1851
Excluded volume	271320 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3t9n__assembly_1__model_1`	heptameric （7）	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) 21 domains

CATH v4.4 (21 domains)

Domain ID domain_id	3t9nA01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nA02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nA03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nB01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nB02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nB03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nC01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nC02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nC03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nD01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nD02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nD03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nE01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nE02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nE03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nF01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nF02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nF03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

Domain ID domain_id	3t9nG01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	1260 —

Domain ID domain_id	3t9nG02
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	30 — SH3 type barrels.
Homologous superfamily homologous superfamily	60 —

Domain ID domain_id	3t9nG03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	100 —

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Unit-cell length a length_a	95.029 Å
Unit-cell length b length_b	138.627 Å
Unit-cell length c length_c	214.580 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	28

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	3.456 Å
Low-resolution limit resolution_low	38.738 Å
R factor r_factor	0.2544
R_work r_work	0.2526
R_free r_free	0.2881

Description description	Small-conductance mechanosensitive channel
Molecular weight formula_weight	32071.7 kDa
Source method src_method	man
Copy count entity_count	7

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F,G
Atom count atom_count	14789

Crystal structure of a membrane protein

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

Small-conductance mechanosensitive channel

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

3t9n__assembly_1__model_1

3t9n__assembly_1__model_1 | I(q)

3t9n__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 non-polymer

6. Fold Classification (SCOP + CATH) 21 domains

CATH v4.4 (21 domains)

7. Citations (1)

Source organism organism	Thermoanaerobacter tengcongensis
NCBI taxonomy ID ncbi_taxonomy_id	119072
Host organism host_organism	Escherichia coli

Description description	DODECYL-BETA-D-MALTOSIDE
Molecular weight formula_weight	510.6 kDa
Source method src_method	syn
Copy count entity_count	2

Crystal structure of a membrane protein

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

Small-conductance mechanosensitive channel

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

3t9n__assembly_1__model_1

3t9n__assembly_1__model_1 | I(q)

3t9n__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 non-polymer

6. Fold Classification (SCOP + CATH) 21 domains

CATH v4.4 (21 domains)

7. Citations (1)