1fnu

STRUCTURE OF STREPTOCOCCAL PYROGENIC EXOTOXIN A

Method: X-RAY DIFFRACTION

▼

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

EXOTOXIN TYPE A PRECURSOR (ALLELE 1)

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	CADMIUM ION × 15 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SPEA_STRPY
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–221； UniProt 1–221 Author chain B； PDBConstruct 1–221； UniProt 1–221 Author chain C； PDBConstruct 1–221； UniProt 1–221 Author chain D； PDBConstruct 1–221； UniProt 1–221

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	1fnu
Deposition date deposition_date	2000-08-23
Structure title title	STRUCTURE OF STREPTOCOCCAL PYROGENIC EXOTOXIN A
Keywords keywords	superantigen, exotoxin A, Toxin; TOXIN
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.

1fnu__assembly_1__model_1

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

Download this curve (.dat)

1fnu__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1fnu__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	30.58 Å
Rg (electron density)	30.26 Å
Total Rg	30.69 Å
Atom count	7307
Residues	884
Excluded volume	130560 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1fnu__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (3)

▼

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1fnua1
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	d1fnua2
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	d1fnub1
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	d1fnub2
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	d1fnuc1
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	d1fnuc2
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	d1fnud1
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	d1fnud2
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

CATH v4.4 (8 domains)

Domain ID domain_id	1fnuA01
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	1fnuA02
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	1fnuB01
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	1fnuB02
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	1fnuC01
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	1fnuC02
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	1fnuD01
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	1fnuD02
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	120 —

▶

Unit-cell length a length_a	55.300 Å
Unit-cell length b length_b	126.800 Å
Unit-cell length c length_c	148.400 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	16

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	1.940 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	—
R_work r_work	0.2233
R_free r_free	0.2810

Description description	EXOTOXIN TYPE A PRECURSOR (ALLELE 1)
Molecular weight formula_weight	25862.1 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	7934

STRUCTURE OF STREPTOCOCCAL PYROGENIC EXOTOXIN A

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

EXOTOXIN TYPE A PRECURSOR (ALLELE 1)

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

1fnu__assembly_1__model_1

1fnu__assembly_1__model_1 | I(q)

1fnu__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)

Description description	CADMIUM ION
Molecular weight formula_weight	112.4 kDa
Source method src_method	syn
Copy count entity_count	15

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	627

STRUCTURE OF STREPTOCOCCAL PYROGENIC EXOTOXIN A

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

EXOTOXIN TYPE A PRECURSOR (ALLELE 1)

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

1fnu__assembly_1__model_1

1fnu__assembly_1__model_1 | I(q)

1fnu__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (1)