2xew

Crystal structure of K11-linked diubiquitin

Method: X-RAY DIFFRACTION

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

UBIQUITIN

HOMO SAPIENS

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	1,2-ETHANEDIOL × 8 CHLORIDE ION × 3 water × 4	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 4	1,2-ETHANEDIOL × 3 CITRATE ANION × 2 water × 4	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 4	1,2-ETHANEDIOL × 6 CHLORIDE ION × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	UBIQ_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–76； UniProt 1–76 Author chain B； PDBConstruct 1–76； UniProt 1–76 Author chain C； PDBConstruct 1–76； UniProt 1–76 Author chain D； PDBConstruct 1–76； UniProt 1–76 Author chain E； PDBConstruct 1–76； UniProt 1–76 Author chain F； PDBConstruct 1–76； UniProt 1–76 Author chain G； PDBConstruct 1–76； UniProt 1–76 Author chain H； PDBConstruct 1–76； UniProt 1–76 Author chain I； PDBConstruct 1–76； UniProt 1–76 Author chain J； PDBConstruct 1–76； UniProt 1–76 Author chain K； PDBConstruct 1–76； UniProt 1–76 Author chain L； PDBConstruct 1–76； UniProt 1–76

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	2xew
Deposition date deposition_date	2010-05-18
Structure title title	Crystal structure of K11-linked diubiquitin
Keywords keywords	PROTEIN DEGRADATION, PROTEASOME, CELL CYCLE, DEUBIQUITINATION; CELL CYCLE
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.

2xew__assembly_1__model_1

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

Download this curve (.dat)

2xew__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2xew__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	21.68 Å
Rg (electron density)	20.89 Å
Total Rg	21.86 Å
Atom count	2413
Residues	302
Excluded volume	43449 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2xew__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2xew__assembly_2__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`2xew__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 (5)

Entity 1 Entity 1 polymer

Description description	UBIQUITIN
Molecular weight formula_weight	8576.8 kDa
Source method src_method	man
Copy count entity_count	12

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F,G,H,I,J,K,L
Atom count atom_count	7931

MQIFVKTLTGKTITLEVEPSDTIENVKAKIQDKEGIPPDQQRLIFAGKQLEDGRTLSDYNIQKESTLHLVLRLRGG

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 non-polymer

Description description	1,2-ETHANEDIOL
Molecular weight formula_weight	62.1 kDa
Source method src_method	syn
Copy count entity_count	17

Entity 3 Entity 3 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	7

Entity 4 Entity 4 non-polymer

Description description	CITRATE ANION
Molecular weight formula_weight	189.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	651

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6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

Domain ID domain_id	d2xewa_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewb_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewc_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewd_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewe_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewf_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewg_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewh_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewi_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewj_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewk_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

Domain ID domain_id	d2xewl_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.1 — Ubiquitin-like
Family Family family	d.15.1.1 — Ubiquitin-related

CATH v4.4 (12 domains)

Domain ID domain_id	2xewA00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewB00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewC00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewD00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewE00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewF00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewG00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewH00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewI00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewJ00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewK00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

Domain ID domain_id	2xewL00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	90 — Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1

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Unit-cell length a length_a	79.230 Å
Unit-cell length b length_b	79.960 Å
Unit-cell length c length_c	221.230 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	48

Space group space_group	P 2 2 21
Space-group number int_tables_number	17
Crystal system crystal_system	—

Resolution resolution	2.200 Å
Low-resolution limit resolution_low	24.918 Å
R factor r_factor	0.2073
R_work r_work	0.2050
R_free r_free	0.2515

Crystal structure of K11-linked diubiquitin

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

UBIQUITIN

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

2xew__assembly_1__model_1

2xew__assembly_1__model_1 | I(q)

2xew__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

CATH v4.4 (12 domains)

7. Citations (1)

Crystal structure of K11-linked diubiquitin

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

UBIQUITIN

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

2xew__assembly_1__model_1

2xew__assembly_1__model_1 | I(q)

2xew__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

CATH v4.4 (12 domains)

7. Citations (1)