SAXSdb — 3pi4

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

Hemoglobin II

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	PROTOPORPHYRIN IX CONTAINING FE × 2 water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 4	PROTOPORPHYRIN IX CONTAINING FE × 4 water × 4	Consistent with protein count
3	Protein homooligomer	Homooligomer	Protein 4	PROTOPORPHYRIN IX CONTAINING FE × 4 water × 4	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 8	PROTOPORPHYRIN IX CONTAINING FE × 8 water × 8	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q86G74_LUCPE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–152； UniProt 2–152 Author chain B； PDBConstruct 2–152； UniProt 2–152

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	3pi4
Deposition date deposition_date	2010-11-05
Structure title title	Crystallographic Structure of HbII-oxy from Lucina pectinata at pH 4.0
Keywords keywords	pH behavior, Oxygen Carrier, OXYGEN TRANSPORT; OXYGEN TRANSPORT
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.

3pi4__assembly_1__model_1

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

Download this curve (.dat)

3pi4__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3pi4__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	20.01 Å
Rg (electron density)	18.77 Å
Total Rg	19.63 Å
Atom count	2425
Residues	302
Excluded volume	43196 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3pi4__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3pi4__assembly_2__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3pi4__assembly_3__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`3pi4__assembly_4__model_1`	octameric （8）	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 (3)

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d3pi4a_
Class class	a — All alpha proteins
Fold Fold fold	a.1 — Globin-like
Superfamily Superfamily superfamily	a.1.1 — Globin-like
Family Family family	a.1.1.0 — automated matches

Domain ID domain_id	d3pi4b_
Class class	a — All alpha proteins
Fold Fold fold	a.1 — Globin-like
Superfamily Superfamily superfamily	a.1.1 — Globin-like
Family Family family	a.1.1.0 — automated matches

CATH v4.4 (2 domains)

Domain ID domain_id	3pi4A00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	490 — Globin-like
Homologous superfamily homologous superfamily	10 — Globins

Domain ID domain_id	3pi4B00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	490 — Globin-like
Homologous superfamily homologous superfamily	10 — Globins

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Unit-cell length a length_a	72.237 Å
Unit-cell length b length_b	72.237 Å
Unit-cell length c length_c	146.288 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 42 21 2
Space-group number int_tables_number	94
Crystal system crystal_system	—

Resolution resolution	3.170 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.1998
R_work r_work	0.1958
R_free r_free	0.2871

Description description	Hemoglobin II
Molecular weight formula_weight	17041.6 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	2452

Crystallographic Structure of HbII-oxy from Lucina pectinata at pH 4.0

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

Hemoglobin II

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

3pi4__assembly_1__model_1

3pi4__assembly_1__model_1 | I(q)

3pi4__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (2)

Description description	PROTOPORPHYRIN IX CONTAINING FE
Molecular weight formula_weight	616.5 kDa
Source method src_method	syn
Copy count entity_count	2

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	6

Crystallographic Structure of HbII-oxy from Lucina pectinata at pH 4.0

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

Hemoglobin II

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

3pi4__assembly_1__model_1

3pi4__assembly_1__model_1 | I(q)

3pi4__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (2)