SAXSdb — 1ihb

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

CYCLIN-DEPENDENT KINASE 6 INHIBITOR

Homo sapiens

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

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CDN2C_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–162； UniProt 1–162 Author chain B； PDBConstruct 1–162； UniProt 1–162

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	1ihb
Deposition date deposition_date	1997-10-25
Structure title title	CRYSTAL STRUCTURE OF P18-INK4C(INK6)
Keywords keywords	CELL CYCLE INHIBITOR, P18-INK4C(INK6), ANKYRIN REPEAT, CDK 4/6 INHIBITOR; CELL CYCLE INHIBITOR
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.

1ihb__assembly_1__model_1

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

Download this curve (.dat)

1ihb__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1ihb__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	26.37 Å
Rg (electron density)	25.71 Å
Total Rg	26.37 Å
Atom count	2382
Residues	312
Excluded volume	41733 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1ihb__assembly_1__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 (2)

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1ihba_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.211 — beta-hairpin-alpha-hairpin repeat
Superfamily Superfamily superfamily	d.211.1 — Ankyrin repeat
Family Family family	d.211.1.1 — Ankyrin repeat

Domain ID domain_id	d1ihbb_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.211 — beta-hairpin-alpha-hairpin repeat
Superfamily Superfamily superfamily	d.211.1 — Ankyrin repeat
Family Family family	d.211.1.1 — Ankyrin repeat

CATH v4.4 (2 domains)

Domain ID domain_id	1ihbA00
Class class	1 — Mainly Alpha
Architecture architecture	25 — Alpha Horseshoe
Topology topology	40 — Serine Threonine Protein Phosphatase 5, Tetratricopeptide repeat
Homologous superfamily homologous superfamily	20 — Ankyrin repeat-containing domain

Domain ID domain_id	1ihbB00
Class class	1 — Mainly Alpha
Architecture architecture	25 — Alpha Horseshoe
Topology topology	40 — Serine Threonine Protein Phosphatase 5, Tetratricopeptide repeat
Homologous superfamily homologous superfamily	20 — Ankyrin repeat-containing domain

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Unit-cell length a length_a	55.510 Å
Unit-cell length b length_b	151.700 Å
Unit-cell length c length_c	40.460 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	8

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

Resolution resolution	1.950 Å
Low-resolution limit resolution_low	8.000 Å
R factor r_factor	0.2090
R_work r_work	0.2090
R_free r_free	0.2890

Description description	CYCLIN-DEPENDENT KINASE 6 INHIBITOR
Molecular weight formula_weight	17564.7 kDa
Source method src_method	man
Copy count entity_count	2

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	2589

CRYSTAL STRUCTURE OF P18-INK4C(INK6)

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

CYCLIN-DEPENDENT KINASE 6 INHIBITOR

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

1ihb__assembly_1__model_1

1ihb__assembly_1__model_1 | I(q)

1ihb__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
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	207

CRYSTAL STRUCTURE OF P18-INK4C(INK6)

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

CYCLIN-DEPENDENT KINASE 6 INHIBITOR

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

1ihb__assembly_1__model_1

1ihb__assembly_1__model_1 | I(q)

1ihb__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)