SAXSdb — 1bun

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

BETA2-BUNGAROTOXIN

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	BETA2-BUNGAROTOXIN × 1 （P00989） SODIUM ION × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PA21B_BUNMU
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–120； UniProt 1–120

BETA2-BUNGAROTOXIN

OrganismNot specified

UniProt P00989

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	BETA2-BUNGAROTOXIN × 1 （P00617） SODIUM ION × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IVB2_BUNMU
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–61； UniProt 25–85

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	1bun
Deposition date deposition_date	1995-10-15
Structure title title	STRUCTURE OF BETA2-BUNGAROTOXIN: POTASSIUM CHANNEL BINDING BY KUNITZ MODULES AND TARGETED PHOSPHOLIPASE ACTION
Keywords keywords	HYDROLASE, PRESYNAPTIC NEUROTOXIN, 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.

1bun__assembly_1__model_1

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

Download this curve (.dat)

1bun__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1bun__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	20.26 Å
Rg (electron density)	19.71 Å
Total Rg	20.48 Å
Atom count	1442
Residues	181
Excluded volume	25320 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1bun__assembly_1__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 (4)

Entity 1 Entity 1 polymer

Description description	BETA2-BUNGAROTOXIN
Molecular weight formula_weight	13521.4 kDa
EC 编号 ec_number	3.1.1.4
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	1523

NLINFMEMIRYTIPCEKTWGEYADYGCYCGAGGSGRPIDALDRCCYVHDNCYGDAEKKHKCNPKTQSYSYKLTKRTIICYGAAGTCARIVCDCDRTAALCFGNSEYIEGHKNIDTARFCQ

Entity 2 Entity 2 polymer

Description description	BETA2-BUNGAROTOXIN
Molecular weight formula_weight	7213.3 kDa
EC 编号 ec_number	3.1.1.4
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

RKRHPDCDKPPDTKICQTVVRAFYYKPSAKRCVQFRYGGCNGNGNHFKSDHLCRCECLEYR

Entity 3 Entity 3 non-polymer

Description description	SODIUM ION
Molecular weight formula_weight	23.0 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	81

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1buna_
Class class	a — All alpha proteins
Fold Fold fold	a.133 — Phospholipase A2, PLA2
Superfamily Superfamily superfamily	a.133.1 — Phospholipase A2, PLA2
Family Family family	a.133.1.2 — Vertebrate phospholipase A2

Domain ID domain_id	d1bunb_
Class class	g — Small proteins
Fold Fold fold	g.8 — BPTI-like
Superfamily Superfamily superfamily	g.8.1 — BPTI-like
Family Family family	g.8.1.1 — Small Kunitz-type inhibitors & BPTI-like toxins

CATH v4.4 (2 domains)

Domain ID domain_id	1bunA00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	90 — Phospholipase A2
Homologous superfamily homologous superfamily	10 — Phospholipase A2 domain

Domain ID domain_id	1bunB00
Class class	4 — Few Secondary Structures
Architecture architecture	10 — Irregular
Topology topology	410 — Factor Xa Inhibitor
Homologous superfamily homologous superfamily	10 — Pancreatic trypsin inhibitor Kunitz domain

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Unit-cell length a length_a	52.600 Å
Unit-cell length b length_b	52.600 Å
Unit-cell length c length_c	177.500 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	8

Space group space_group	P 43 2 2
Space-group number int_tables_number	95
Crystal system crystal_system	—

Resolution resolution	2.450 Å
Low-resolution limit resolution_low	5.000 Å
R factor r_factor	0.1930
R_work r_work	0.1930
R_free r_free	0.2810

STRUCTURE OF BETA2-BUNGAROTOXIN: POTASSIUM CHANNEL BINDING BY KUNITZ MODULES AND TARGETED PHOSPHOLIPASE ACTION

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

BETA2-BUNGAROTOXIN

State in the Current Structure

Other States of the Same Protein in the Database

BETA2-BUNGAROTOXIN

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

1bun__assembly_1__model_1

1bun__assembly_1__model_1 | I(q)

1bun__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

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

STRUCTURE OF BETA2-BUNGAROTOXIN: POTASSIUM CHANNEL BINDING BY KUNITZ MODULES AND TARGETED PHOSPHOLIPASE ACTION

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

BETA2-BUNGAROTOXIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

BETA2-BUNGAROTOXIN

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

1bun__assembly_1__model_1

1bun__assembly_1__model_1 | I(q)

1bun__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

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)