SAXSdb — 1u4f

▼

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

Inward rectifier potassium channel 2

Mus musculus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	water × 4	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 8	water × 8	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IRK2_MOUSE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 7–29； UniProt 41–63 Author chain A； PDBConstruct 30–270； UniProt 188–428 Author chain B； PDBConstruct 7–29； UniProt 41–63 Author chain B； PDBConstruct 30–270； UniProt 188–428 Author chain C； PDBConstruct 7–29； UniProt 41–63 Author chain C； PDBConstruct 30–270； UniProt 188–428 Author chain D； PDBConstruct 7–29； UniProt 41–63 Author chain D； PDBConstruct 30–270； UniProt 188–428

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.

▼

2. Structure Basics 2. Structure Basics

Entry ID entry_id	1u4f
Deposition date deposition_date	2004-07-24
Structure title title	Crystal Structure of Cytoplasmic Domains of IRK1 (Kir2.1) channel
Keywords keywords	cytoplasmic domain, Kir2.1, IRK1, inwardly rectifying K channel, rectification, ALLERGEN; ALLERGEN
Experimental Method method	X-RAY DIFFRACTION

▼

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.

1u4f__assembly_2__model_1

Assembly 2 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1u4f__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1u4f__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	36.79 Å
Rg (electron density)	35.91 Å
Total Rg	36.43 Å
Atom count	12640
Residues	1568
Excluded volume	224680 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1u4f__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1u4f__assembly_2__model_1`	octameric （8）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (2)

▼

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1u4fa_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.18 — E set domains
Family Family family	b.1.18.16 — Cytoplasmic domain of inward rectifier potassium channel

Domain ID domain_id	d1u4fb_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.18 — E set domains
Family Family family	b.1.18.16 — Cytoplasmic domain of inward rectifier potassium channel

Domain ID domain_id	d1u4fc_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.18 — E set domains
Family Family family	b.1.18.16 — Cytoplasmic domain of inward rectifier potassium channel

Domain ID domain_id	d1u4fd_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.18 — E set domains
Family Family family	b.1.18.16 — Cytoplasmic domain of inward rectifier potassium channel

CATH v4.4 (4 domains)

Domain ID domain_id	1u4fA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1400 — G protein-activated inward rectifier potassium channel 1

Domain ID domain_id	1u4fB01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1400 — G protein-activated inward rectifier potassium channel 1

Domain ID domain_id	1u4fC01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1400 — G protein-activated inward rectifier potassium channel 1

Domain ID domain_id	1u4fD01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1400 — G protein-activated inward rectifier potassium channel 1

▶

Unit-cell length a length_a	112.461 Å
Unit-cell length b length_b	138.294 Å
Unit-cell length c length_c	138.745 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	32

Space group space_group	C 2 2 21
Space-group number int_tables_number	20
Crystal system crystal_system	—

Resolution resolution	2.410 Å
Low-resolution limit resolution_low	38.440 Å
R factor r_factor	—
R_work r_work	0.2250
R_free r_free	0.2810

Description description	Inward rectifier potassium channel 2
Molecular weight formula_weight	30840.6 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	6533

Crystal Structure of Cytoplasmic Domains of IRK1 (Kir2.1) channel

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

Inward rectifier potassium channel 2

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

1u4f__assembly_2__model_1

1u4f__assembly_2__model_1 | I(q)

1u4f__assembly_2__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) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)

Source organism organism	Mus musculus
Common name common_name	house mouse
NCBI taxonomy ID ncbi_taxonomy_id	10090
Host organism host_organism	Escherichia coli BL21(DE3)

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	213

Crystal Structure of Cytoplasmic Domains of IRK1 (Kir2.1) channel

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

Inward rectifier potassium channel 2

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

1u4f__assembly_2__model_1

1u4f__assembly_2__model_1 | I(q)

1u4f__assembly_2__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) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (1)