4fo2

Heat-labile enterotoxin LT-IIb-B5(T13I) mutant

Method: X-RAY DIFFRACTION

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

Heat-labile enterotoxin IIB, B chain

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 5	SODIUM ION × 2 water × 5	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 5	SODIUM ION × 2 water × 5	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 5	SODIUM ION × 2 ACETATE ION × 1 water × 5	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 5	SODIUM ION × 2 ACETATE ION × 1 water × 5	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	E2BB_ECOLX
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–98； UniProt 24–121 Author chain B； PDBConstruct 1–98； UniProt 24–121 Author chain C； PDBConstruct 1–98； UniProt 24–121 Author chain D； PDBConstruct 1–98； UniProt 24–121 Author chain E； PDBConstruct 1–98； UniProt 24–121 Author chain F； PDBConstruct 1–98； UniProt 24–121 Author chain G； PDBConstruct 1–98； UniProt 24–121 Author chain H； PDBConstruct 1–98； UniProt 24–121 Author chain I； PDBConstruct 1–98； UniProt 24–121 Author chain J； PDBConstruct 1–98； UniProt 24–121 Author chain K； PDBConstruct 1–98； UniProt 24–121 Author chain L； PDBConstruct 1–98； UniProt 24–121 Author chain M； PDBConstruct 1–98； UniProt 24–121 Author chain N； PDBConstruct 1–98； UniProt 24–121 Author chain O； PDBConstruct 1–98； UniProt 24–121 Author chain P； PDBConstruct 1–98； UniProt 24–121 Author chain Q； PDBConstruct 1–98； UniProt 24–121 Author chain R； PDBConstruct 1–98； UniProt 24–121 Author chain S； PDBConstruct 1–98； UniProt 24–121 Author chain T； PDBConstruct 1–98； UniProt 24–121

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	4fo2
Deposition date deposition_date	2012-06-20
Structure title title	Heat-labile enterotoxin LT-IIb-B5(T13I) mutant
Keywords keywords	B pentamer of LT-IIb T13I mutant, TOXIN; TOXIN
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.

4fo2__assembly_1__model_1

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

Download this curve (.dat)

4fo2__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

4fo2__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	24.08 Å
Rg (electron density)	22.86 Å
Total Rg	23.59 Å
Atom count	3707
Residues	490
Excluded volume	65875 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`4fo2__assembly_1__model_1`	pentameric （5）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`4fo2__assembly_2__model_1`	pentameric （5）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`4fo2__assembly_3__model_1`	pentameric （5）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`4fo2__assembly_4__model_1`	pentameric （5）	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 (4)

Entity 1 Entity 1 polymer

Description description	Heat-labile enterotoxin IIB, B chain
Molecular weight formula_weight	10661.1 kDa
Mutation mutation	T13I
Source method src_method	man
Copy count entity_count	20

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D,E,F,G,H,A,B,C,I,J,K,L,M,N,O,P,Q,R,S,T
Atom count atom_count	15396

GASQFFKDNCNRITASLVEGVELTKYISDINNNTDGMYVVSSTGGVWRISRAKDYPDNVMTAEMRKIAMAAVLSGMRVNMCASPASSPNVIWAIELEA

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 3 Entity 3 non-polymer

Description description	ACETATE ION
Molecular weight formula_weight	59.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	395

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6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

Domain ID domain_id	d4fo2a_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2b_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2c_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2d_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2e_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2f_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2g_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2h_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2i_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2j_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2k_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2l_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2m_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2n_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2o_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2p_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2q_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2r_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2s_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

Domain ID domain_id	d4fo2t_
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.40.2.1 — Bacterial AB5 toxins, B-subunits

CATH v4.4 (20 domains)

Domain ID domain_id	4fo2A00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2B00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2C00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2D00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2E00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2F00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2G00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2H00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2I00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2J00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2K00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2L00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2M00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2N00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2O00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2P00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2Q00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2R00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2S00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	4fo2T00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	50 —

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Unit-cell length a length_a	119.310 Å
Unit-cell length b length_b	119.976 Å
Unit-cell length c length_c	142.446 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.05 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	80

Space group space_group	C 1 2 1
Space-group number int_tables_number	5
Crystal system crystal_system	—

Resolution resolution	1.500 Å
Low-resolution limit resolution_low	45.740 Å
R factor r_factor	0.2247
R_work r_work	0.2229
R_free r_free	0.2588

Heat-labile enterotoxin LT-IIb-B5(T13I) mutant

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

Heat-labile enterotoxin IIB, B 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

4fo2__assembly_1__model_1

4fo2__assembly_1__model_1 | I(q)

4fo2__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 (4)

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 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)

Heat-labile enterotoxin LT-IIb-B5(T13I) mutant

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

Heat-labile enterotoxin IIB, B 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

4fo2__assembly_1__model_1

4fo2__assembly_1__model_1 | I(q)

4fo2__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 (4)

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 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)