3al4

Crystal structure of the swine-origin A (H1N1)-2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus

Method: X-RAY DIFFRACTION

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

Hemagglutinin

Influenza A virus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Homooligomer	Protein 2 其他Polymer 2	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 2 2-acetamido-2-deoxy-beta-D-glucopyranose × 2 water × 2	Consistent with protein count
2	Other combination	Homooligomer	Protein 2 其他Polymer 2	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 2 water × 2	Consistent with protein count
3	Other combination	Homooligomer	Protein 2 其他Polymer 1	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 4 water × 2	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 2	2-acetamido-2-deoxy-beta-D-glucopyranose × 3 water × 2	Consistent with protein count
5	Other combination	Homooligomer	Protein 2 其他Polymer 2	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 water × 2	Consistent with protein count
6	Protein homooligomer	Homooligomer	Protein 2	2-acetamido-2-deoxy-beta-D-glucopyranose × 5 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	C3W5S1_I09A0
Isoform	—
PDB entities	1, 2
Chains and sequence ranges	Author chain A； PDBConstruct 7–333； UniProt 18–344 Author chain C； PDBConstruct 7–333； UniProt 18–344 Author chain E； PDBConstruct 7–333； UniProt 18–344 Author chain G； PDBConstruct 7–333； UniProt 18–344 Author chain I； PDBConstruct 7–333； UniProt 18–344 Author chain K； PDBConstruct 7–333； UniProt 18–344 Author chain B； PDBConstruct 1–176； UniProt 345–520 Author chain D； PDBConstruct 1–176； UniProt 345–520 Author chain F； PDBConstruct 1–176； UniProt 345–520 Author chain H； PDBConstruct 1–176； UniProt 345–520 Author chain J； PDBConstruct 1–176； UniProt 345–520 Author chain L； PDBConstruct 1–176； UniProt 345–520

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	3al4
Deposition date deposition_date	2010-07-22
Structure title title	Crystal structure of the swine-origin A (H1N1)-2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus
Keywords keywords	TRIMER, ENVELOPE PROTEIN, HEMAGGLUTININ, VIRAL PROTEIN-VIRAL PROTEIN complex; VIRAL PROTEIN/VIRAL PROTEIN
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.

3al4__assembly_1__model_1

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

Download this curve (.dat)

3al4__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3al4__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	36.17 Å
Rg (electron density)	36.82 Å
Total Rg	36.61 Å
Atom count	3894
Residues	483
Excluded volume	68804 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3al4__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3al4__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3al4__assembly_3__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`3al4__assembly_4__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
5	1	`3al4__assembly_5__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
6	1	`3al4__assembly_6__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 (6)

Entity 1 Entity 1 polymer

Description description	Hemagglutinin
Molecular weight formula_weight	36989.7 kDa
Source method src_method	man
Copy count entity_count	6

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C,E,G,I,K
Atom count atom_count	23626

ADLGSRDTLCIGYHANNSTDTVDTVLEKNVTVTHSVNLLEDKHNGKLCKLRGVAPLHLGKCNIAGWILGNPECESLSTASSWSYIVETPSSDNGTCYPGDFIDYEELREQLSSVSSFERFEIFPKTSSWPNHDSNKGVTAACPHAGAKSFYKNLIWLVKKGNSYPKLSKSYINDKGKEVLVLWGIHHPSTSADQQSLYQNADTYVFVGSSRYSKKFKPEIAIRPKVRDQEGRMNYYWTLVEPGDKITFEATGNLVVPRYAFAMERNAGSGIIISDTPVHDCNTTCQTPKGAINTSLPFQNIHPITIGKCPKYVKSTKLRLATGLRNIPSIQSR

Source Source

Source organism organism	Influenza A virus
NCBI taxonomy ID ncbi_taxonomy_id	641501
Host organism host_organism	Spodoptera frugiperda

Entity 2 Entity 2 polymer

Description description	Hemagglutinin
Molecular weight formula_weight	20757.0 kDa
Source method src_method	man
Copy count entity_count	6

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D,F,H,J,L

GLFGAIAGFIEGGWTGMVDGWYGYHHQNEQGSGYAADLKSTQNAIDEITNKVNSVIEKMNTQFTAVGKEFNHLEKRIENLNKKVDDGFLDIWTYNAELLVLLENERTLDYHDSNVKNLYEKVRSQLKNNAKEIGNGCFEFYHKCDNTCMESVKNGTYDYPKYSEEAKLNREEIDGVRLVPR

Source Source

Source organism organism	Influenza A virus
NCBI taxonomy ID ncbi_taxonomy_id	641501
Host organism host_organism	Spodoptera frugiperda

Entity 3 Entity 3 branched

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	424.4 kDa
Source method src_method	man
Copy count entity_count	5

Entity 4 Entity 4 branched

Description description	beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	586.5 kDa
Source method src_method	man
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	221.2 kDa
Source method src_method	man
Copy count entity_count	16

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	317

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6. Fold Classification (SCOP + CATH) 30 domains

SCOP 2.08 (12 domains)

Domain ID domain_id	d3al4a_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4b_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

Domain ID domain_id	d3al4c_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4d_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

Domain ID domain_id	d3al4e_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4f_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

Domain ID domain_id	d3al4g_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4h_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

Domain ID domain_id	d3al4i_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4j_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

Domain ID domain_id	d3al4k_
Class class	b — All beta proteins
Fold Fold fold	b.19 — Viral protein domain
Superfamily Superfamily superfamily	b.19.1 — Viral protein domain
Family Family family	b.19.1.2 — Influenza hemagglutinin headpiece

Domain ID domain_id	d3al4l_
Class class	h — Coiled coil proteins
Fold Fold fold	h.3 — Stalk segment of viral fusion proteins
Superfamily Superfamily superfamily	h.3.1 — Influenza hemagglutinin (stalk)
Family Family family	h.3.1.1 — Influenza hemagglutinin (stalk)

CATH v4.4 (18 domains)

Domain ID domain_id	3al4A01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4A02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4B00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3al4C01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4C02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4D00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3al4E01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4E02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4F00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3al4G01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4G02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4H00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3al4I01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4I02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4J00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3al4K01
Class class	2 — Mainly Beta
Architecture architecture	10 — Ribbon
Topology topology	77 — Hemagglutinin; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Hemagglutinin Chain A, Domain 2

Domain ID domain_id	3al4K02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	209 — Hemagglutinin (Ha1 Chain); Chain: A; domain 1
Homologous superfamily homologous superfamily	20 — Haemagglutinin, alpha/beta domain, HA1 chain

Domain ID domain_id	3al4L00
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	20 — Hemagglutinin Ectodomain; Chain B
Homologous superfamily homologous superfamily	10 —

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Unit-cell length a length_a	66.020 Å
Unit-cell length b length_b	115.190 Å
Unit-cell length c length_c	114.985 Å
Unit-cell angle α angle_alpha	62.31 °
Unit-cell angle β angle_beta	77.94 °
Unit-cell angle γ angle_gamma	81.05 °
Molecules per unit cell Z z_pdb	6

Space group space_group	P 1
Space-group number int_tables_number	1
Crystal system crystal_system	—

Resolution resolution	2.872 Å
Low-resolution limit resolution_low	24.190 Å
R factor r_factor	0.2470
R_work r_work	0.2460
R_free r_free	0.2700

Crystal structure of the swine-origin A (H1N1)-2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus

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

Hemagglutinin

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

3al4__assembly_1__model_1

3al4__assembly_1__model_1 | I(q)

3al4__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 (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 branched

Entity 4 Entity 4 branched

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 30 domains

SCOP 2.08 (12 domains)

CATH v4.4 (18 domains)

7. Citations (1)

Crystal structure of the swine-origin A (H1N1)-2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus

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

Hemagglutinin

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

3al4__assembly_1__model_1

3al4__assembly_1__model_1 | I(q)

3al4__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 (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 branched

Entity 4 Entity 4 branched

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 30 domains

SCOP 2.08 (12 domains)

CATH v4.4 (18 domains)

7. Citations (1)