SAXSdb — 1pbi

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

BOWMAN-BIRK PROTEINASE INHIBITOR

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	water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	IBBB_PEA
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–72； UniProt 1–72 Author chain B； PDBConstruct 1–72； UniProt 1–72

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	1pbi
Deposition date deposition_date	1998-08-20
Structure title title	CRYSTAL STRUCTURE OF A BOWMAN-BIRK INHIBITOR FROM PEA SEEDS
Keywords keywords	BOWMAN-BIRK INHIBITOR, TRYPSIN INHIBITOR, CHYMOTRYPSIN INHIBITOR; BOWMAN-BIRK INHIBITOR
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.

1pbi__assembly_1__model_1

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

Download this curve (.dat)

1pbi__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1pbi__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	22.78 Å
Rg (electron density)	22.55 Å
Total Rg	23.10 Å
Atom count	1922
Residues	272
Excluded volume	33637 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1pbi__assembly_1__model_1`	tetrameric （4）	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 (2)

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1pbia_
Class class	g — Small proteins
Fold Fold fold	g.3 — Knottins (small inhibitors, toxins, lectins)
Superfamily Superfamily superfamily	g.3.13 — Bowman-Birk inhibitor, BBI
Family Family family	g.3.13.1 — Bowman-Birk inhibitor, BBI

Domain ID domain_id	d1pbib_
Class class	g — Small proteins
Fold Fold fold	g.3 — Knottins (small inhibitors, toxins, lectins)
Superfamily Superfamily superfamily	g.3.13 — Bowman-Birk inhibitor, BBI
Family Family family	g.3.13.1 — Bowman-Birk inhibitor, BBI

CATH v4.4 (2 domains)

Domain ID domain_id	1pbiA00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	69 — Cysteine Protease (Bromelain) Inhibitor, subunit H
Homologous superfamily homologous superfamily	10 — Cysteine Protease (Bromelain) Inhibitor, subunit H

Domain ID domain_id	1pbiB00
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	69 — Cysteine Protease (Bromelain) Inhibitor, subunit H
Homologous superfamily homologous superfamily	10 — Cysteine Protease (Bromelain) Inhibitor, subunit H

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Unit-cell length a length_a	52.680 Å
Unit-cell length b length_b	52.680 Å
Unit-cell length c length_c	135.300 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 41 21 2
Space-group number int_tables_number	92
Crystal system crystal_system	—

Resolution resolution	2.700 Å
Low-resolution limit resolution_low	7.000 Å
R factor r_factor	0.2140
R_work r_work	0.2140
R_free r_free	0.2720

Description description	BOWMAN-BIRK PROTEINASE INHIBITOR
Molecular weight formula_weight	7930.1 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	994

CRYSTAL STRUCTURE OF A BOWMAN-BIRK INHIBITOR FROM PEA SEEDS

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

BOWMAN-BIRK PROTEINASE INHIBITOR

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

1pbi__assembly_1__model_1

1pbi__assembly_1__model_1 | I(q)

1pbi__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

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	33

CRYSTAL STRUCTURE OF A BOWMAN-BIRK INHIBITOR FROM PEA SEEDS

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

BOWMAN-BIRK PROTEINASE INHIBITOR

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

1pbi__assembly_1__model_1

1pbi__assembly_1__model_1 | I(q)

1pbi__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

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)