1ktk

Complex of Streptococcal pyrogenic enterotoxin C (SpeC) with a human T cell receptor beta chain (Vbeta2.1)

Method: X-RAY DIFFRACTION

▼

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

Exotoxin type C

Streptococcus pyogenes

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 6	T-cell receptor beta chain × 2 （P01850）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SPEC_STRPY
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–208； UniProt 28–235 Author chain B； PDBConstruct 1–208； UniProt 28–235 Author chain C； PDBConstruct 1–208； UniProt 28–235 Author chain D； PDBConstruct 1–208； UniProt 28–235

T-cell receptor beta chain

Homo sapiens

UniProt P01850

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 6	Exotoxin type C × 4 （P13380）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TCB_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain E； PDBConstruct 1–247； UniProt 1–130 Author chain F； PDBConstruct 1–247； UniProt 1–130

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	1ktk
Deposition date deposition_date	2002-01-16
Structure title title	Complex of Streptococcal pyrogenic enterotoxin C (SpeC) with a human T cell receptor beta chain (Vbeta2.1)
Keywords keywords	Streptococcus, immunity, T cell receptor beta, IMMUNE SYSTEM; IMMUNE SYSTEM
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.

1ktk__assembly_1__model_1

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

Download this curve (.dat)

1ktk__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1ktk__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	44.90 Å
Rg (electron density)	44.93 Å
Total Rg	44.87 Å
Atom count	9511
Residues	1200
Excluded volume	168420 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1ktk__assembly_1__model_1`	hexameric （6）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (2)

Entity 1 Entity 1 polymer

Description description	Exotoxin type C
Molecular weight formula_weight	24384.3 kDa
Mutation mutation	H35A
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	9511

DSKKDISNVKSDLLYAYTITPYDYKDCRVNFSTTHTLNIDTQKYRGKDYYISSEMSYEASQKFKRDDHVDVFGLFYILNSHTGEYIYGGITPAQNNKVNHKLLGNLFISGESQQNLNNKIILEKDIVTFQEIDFKIRKYLMDNYKIYDATSPYVSGRIEIGTKDGKHEQIDLFDSPNEGTRSDIFAKYKDNRIINMKNFSHFDIYLEK

Source Source

Source organism organism	Streptococcus pyogenes
NCBI taxonomy ID ncbi_taxonomy_id	1314
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	T-cell receptor beta chain
Molecular weight formula_weight	27461.6 kDa
Mutation mutation	C13A, C191A
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	E,F

GAVVSQHPSRVIAKSGTSVKIECRSLDFQATTMFWYRQFPKQSLMLMATSAEGSKATYEQGVEKDKFLINHASLTLSTLTVTSAHPEDSSFYICSALAGSGSSTDTQYFGPGTRLTVLEDLKNFPPEVAVFEPSEAEISHTQKATLVCLATGFYPDHVELSWWVNGKEVHSGVSTDPQPLKEQPALNDSRYALSSRLRVSATFWQNPRNHFRCQVQFYGLSENDEWTQDRAKPVTQIVSAEAWGRAD

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

▼

6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

Domain ID domain_id	d1ktka1
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	d1ktka2
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	d1ktkb1
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	d1ktkb2
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	d1ktkc1
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	d1ktkc2
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	d1ktkd1
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	d1ktkd2
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	d1ktke1
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	d1ktke2
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.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d1ktkf1
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	d1ktkf2
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.1.1.2 — C1 set domains (antibody constant domain-like)

CATH v4.4 (12 domains)

Domain ID domain_id	1ktkA01
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	1ktkA02
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	1ktkB01
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	1ktkB02
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	1ktkC01
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	1ktkC02
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	1ktkD01
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	1ktkD02
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	1ktkE01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktkE02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktkF01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1ktkF02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

▶

Unit-cell length a length_a	57.378 Å
Unit-cell length b length_b	146.764 Å
Unit-cell length c length_c	135.690 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	98.61 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	3.000 Å
Low-resolution limit resolution_low	6.000 Å
R factor r_factor	0.3260
R_work r_work	0.3260
R_free r_free	0.3340

Complex of Streptococcal pyrogenic enterotoxin C (SpeC) with a human T cell receptor beta chain (Vbeta2.1)

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

Exotoxin type C

State in the Current Structure

Other States of the Same Protein in the Database

T-cell receptor beta chain

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

1ktk__assembly_1__model_1

1ktk__assembly_1__model_1 | I(q)

1ktk__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 polymer

Polymer Polymer

Source Source

6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

CATH v4.4 (12 domains)

7. Citations (1)

Complex of Streptococcal pyrogenic enterotoxin C (SpeC) with a human T cell receptor beta chain (Vbeta2.1)

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

Exotoxin type C

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

T-cell receptor beta chain

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

1ktk__assembly_1__model_1

1ktk__assembly_1__model_1 | I(q)

1ktk__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 polymer

Polymer Polymer

Source Source

6. Fold Classification (SCOP + CATH) 24 domains

SCOP 2.08 (12 domains)

CATH v4.4 (12 domains)

7. Citations (1)