3r8b

Crystal structure of Staphylococcal Enterotoxin B in complex with an affinity matured mouse TCR VBeta8.2 protein, G5-8

Method: X-RAY DIFFRACTION

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

Enterotoxin type B

Staphylococcus aureus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 3 SULFATE ION × 1 ZINC ION × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 3 ZINC ION × 3	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 ZINC ION × 3	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 1 ZINC ION × 3	Consistent with protein count
5	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 3 ZINC ION × 4	Consistent with protein count
6	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 1 ZINC ION × 3	Consistent with protein count
7	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 2 ZINC ION × 3	Consistent with protein count
8	Protein heterocomplex	Heteromer	Protein 2	G5-8 × 1 CHLORIDE ION × 1 ZINC ION × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	ETXB_STAAU
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–239； UniProt 28–266 Author chain C； PDBConstruct 1–239； UniProt 28–266 Author chain E； PDBConstruct 1–239； UniProt 28–266 Author chain G； PDBConstruct 1–239； UniProt 28–266 Author chain I； PDBConstruct 1–239； UniProt 28–266 Author chain K； PDBConstruct 1–239； UniProt 28–266 Author chain M； PDBConstruct 1–239； UniProt 28–266 Author chain O； PDBConstruct 1–239； UniProt 28–266

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	3r8b
Deposition date deposition_date	2011-03-23
Structure title title	Crystal structure of Staphylococcal Enterotoxin B in complex with an affinity matured mouse TCR VBeta8.2 protein, G5-8
Keywords keywords	immunoglobulin-like, OB-fold, TOXIN-IMMUNE SYSTEM complex; TOXIN/IMMUNE SYSTEM
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.

3r8b__assembly_8__model_1

Assembly 8 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

3r8b__assembly_8__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3r8b__assembly_8__model_1 | P(r) · Pending

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

Rg（Guinier）	22.58 Å
Rg (electron density)	21.78 Å
Total Rg	22.68 Å
Atom count	2730
Residues	336
Excluded volume	48495 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3r8b__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3r8b__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3r8b__assembly_3__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`3r8b__assembly_4__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
5	1	`3r8b__assembly_5__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
6	1	`3r8b__assembly_6__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
7	1	`3r8b__assembly_7__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
8	1	`3r8b__assembly_8__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 (5)

Entity 1 Entity 1 polymer

Description description	Enterotoxin type B
Molecular weight formula_weight	28411.1 kDa
Source method src_method	man
Copy count entity_count	8

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C,E,G,I,K,M,O
Atom count atom_count	21911

ESQPDPKPDELHKSSKFTGLMENMKVLYDDNHVSAINVKSIDQFLYFDLIYSIKDTKLGNYDNVRVEFKNKDLADKYKDKYVDVFGANYYYQCYFSKKTNDINSHQTDKRKTCMYGGVTEHNGNQLDKYRSITVRVFEDGKNLLSFDVQTNKKKVTAQELDYLTRHYLVKNKKLYEFNNSPYETGYIKFIENENSFWYDMMPAPGDKFDQSKYLMMYNDNKMVDSKDVKIEVYLTTKKK

Source Source

Source organism organism	Staphylococcus aureus
NCBI taxonomy ID ncbi_taxonomy_id	1280
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	G5-8
Molecular weight formula_weight	13821.5 kDa
Source method src_method	man
Copy count entity_count	8

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D,F,H,J,L,N,P

MARLEAAVTQSPRNKVAVTGEKVTLSCKQTNSYFNNMYWYRQDTGHELRLIFMSHGIRNVEKGDIPDGYKASRPSQENFSLILELATPSQTSVYFCASGGGGTLYFGAGTRLSVLYGSSRVDLQP

Source Source

Source organism organism	Rattus norvegicus
Common name common_name	rat
NCBI taxonomy ID ncbi_taxonomy_id	10116
Host organism host_organism	Escherichia coli

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	14

Entity 4 Entity 4 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 5 Entity 5 non-polymer

Description description	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	24

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6. Fold Classification (SCOP + CATH) 48 domains

SCOP 2.08 (24 domains)

Domain ID domain_id	d3r8ba1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8ba2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bb_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bc1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bc2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bd_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8be1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8be2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bf_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bg1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bg2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bh_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bi1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bi2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bj_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bk1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bk2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bl_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bm1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bm2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bn_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3r8bo1
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.2 — Bacterial enterotoxins
Family Family family	b.40.2.2 — Superantigen toxins, N-terminal domain

Domain ID domain_id	d3r8bo2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.6 — Superantigen toxins, C-terminal domain
Family Family family	d.15.6.1 — Superantigen toxins, C-terminal domain

Domain ID domain_id	d3r8bp_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

CATH v4.4 (24 domains)

Domain ID domain_id	3r8bA01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bA02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bB00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bC01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bC02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bD00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bE01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bE02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bF00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bG01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bG02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bH00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bI01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bI02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bJ00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bK01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bK02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bL00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bM01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bM02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bN00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3r8bO01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	3r8bO02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	110 —

Domain ID domain_id	3r8bP00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

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Unit-cell length a length_a	109.954 Å
Unit-cell length b length_b	160.370 Å
Unit-cell length c length_c	186.265 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	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	2.950 Å
Low-resolution limit resolution_low	46.570 Å
R factor r_factor	0.2470
R_work r_work	0.2461
R_free r_free	0.2655

Crystal structure of Staphylococcal Enterotoxin B in complex with an affinity matured mouse TCR VBeta8.2 protein, G5-8

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

Enterotoxin type B

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

3r8b__assembly_8__model_1

3r8b__assembly_8__model_1 | I(q)

3r8b__assembly_8__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

6. Fold Classification (SCOP + CATH) 48 domains

SCOP 2.08 (24 domains)

CATH v4.4 (24 domains)

7. Citations (1)

Crystal structure of Staphylococcal Enterotoxin B in complex with an affinity matured mouse TCR VBeta8.2 protein, G5-8

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

Enterotoxin type B

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

3r8b__assembly_8__model_1

3r8b__assembly_8__model_1 | I(q)

3r8b__assembly_8__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

6. Fold Classification (SCOP + CATH) 48 domains

SCOP 2.08 (24 domains)

CATH v4.4 (24 domains)

7. Citations (1)