3qa3

Crystal Structure of A-domain in complex with antibody

Method: X-RAY DIFFRACTION

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

Integrin alpha-M

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 3	Antibody Light chain × 1 Antibody Heavy chain × 1 1,2-ETHANEDIOL × 4 GLYCEROL × 3 CALCIUM ION × 1 water × 3	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 3	Antibody Light chain × 1 Antibody Heavy chain × 1 GLYCEROL × 2 CALCIUM ION × 1 water × 3	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 3	Antibody Light chain × 1 Antibody Heavy chain × 1 1,2-ETHANEDIOL × 1 CALCIUM ION × 1 water × 3	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 3	Antibody Light chain × 1 Antibody Heavy chain × 1 1,2-ETHANEDIOL × 3 CALCIUM ION × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	ITAM_HUMAN
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain E； PDBConstruct 1–190； UniProt 148–337 Author chain G； PDBConstruct 1–190； UniProt 148–337 Author chain I； PDBConstruct 1–190； UniProt 148–337 Author chain L； PDBConstruct 1–190； UniProt 148–337

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	3qa3
Deposition date deposition_date	2011-01-10
Structure title title	Crystal Structure of A-domain in complex with antibody
Keywords keywords	IMMUNE SYSTEM- cell adhesion complex; IMMUNE SYSTEM/ cell adhesion
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.

3qa3__assembly_4__model_1

Assembly 4 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

3qa3__assembly_4__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3qa3__assembly_4__model_1 | P(r) · Pending

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

Rg（Guinier）	32.98 Å
Rg (electron density)	33.01 Å
Total Rg	33.44 Å
Atom count	4914
Residues	629
Excluded volume	87110 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3qa3__assembly_1__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3qa3__assembly_2__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3qa3__assembly_3__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`3qa3__assembly_4__model_1`	trimeric （3）	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 (7)

Entity 1 Entity 1 polymer

Description description	Antibody Light chain
Molecular weight formula_weight	24457.0 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C,A,F,J
Atom count atom_count	19772

DIEMTQSPSSLGVSVGEKVTMSCKSSQNLLYSSNQKNYLAWYQQKPGQSPKLLIYWASTRESGVPDRFTGTGSGTDFTLTISSVKAEDLAVYYCQQYYSYPLTFGAGTKLELKRADAAPTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLNSWTDQDSKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRNEC

Entity 2 Entity 2 polymer

Description description	Antibody Heavy chain
Molecular weight formula_weight	24043.8 kDa
Source method src_method	nat
Copy count entity_count	4

Polymer Polymer

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

QVQLQQSGAELVKPGASVKLSCTPSGFNIKDIYMQWVKQRPEQGLEWIGRIDPANDKTKYDPKFQGKATITADTSSNTAYLQLSSLTSEDTAVYYCASEGHYGYDGYAMDYWGQGTTVTVSSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAVLQSDLYTLSSSVTVPSSPRPSETVTCNVAHPASSTKVDKKIVPRDC

Entity 3 Entity 3 polymer

Description description	Integrin alpha-M
Molecular weight formula_weight	21722.8 kDa
Mutation mutation	I316G
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	G,E,I,L

DSDIAFLIDGSGSIIPHDFRRMKEFVSTVMEQLKKSKTLFSLMQYSEEFRIHFTFKEFQNNPNPRSLVKPITQLLGRTHTATGIRKVVRELFNITNGARKNAFKILVVITDGEKFGDPLGYEDVIPEADREGVIRYVIGVGDAFRSEKSRQELNTIASKPPRDHVFQVNNFEALKTIQNQLREKGFAIEG

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 non-polymer

Description description	1,2-ETHANEDIOL
Molecular weight formula_weight	62.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 5 Entity 5 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	syn
Copy count entity_count	5

Entity 6 Entity 6 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	75

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6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

Domain ID domain_id	d3qa3a1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3a2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d3qa3b1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3b2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d3qa3c1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3c2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d3qa3d1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3d2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d3qa3e_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.62 — vWA-like
Superfamily Superfamily superfamily	c.62.1 — vWA-like
Family Family family	c.62.1.1 — Integrin A (or I) domain

Domain ID domain_id	d3qa3f1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3f2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d3qa3g_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.62 — vWA-like
Superfamily Superfamily superfamily	c.62.1 — vWA-like
Family Family family	c.62.1.1 — Integrin A (or I) domain

Domain ID domain_id	d3qa3h1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3h2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d3qa3i_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.62 — vWA-like
Superfamily Superfamily superfamily	c.62.1 — vWA-like
Family Family family	c.62.1.1 — Integrin A (or I) domain

Domain ID domain_id	d3qa3j1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3j2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d3qa3k1
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.1 — V set domains (antibody variable domain-like)

Domain ID domain_id	d3qa3k2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d3qa3l_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.62 — vWA-like
Superfamily Superfamily superfamily	c.62.1 — vWA-like
Family Family family	c.62.1.1 — Integrin A (or I) domain

CATH v4.4 (20 domains)

Domain ID domain_id	3qa3A01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3A02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3B01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3B02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3C01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3C02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3D01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3D02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3E00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	410 — von Willebrand factor, type A domain

Domain ID domain_id	3qa3F01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3F02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3G00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	410 — von Willebrand factor, type A domain

Domain ID domain_id	3qa3H01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3H02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3I00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	410 — von Willebrand factor, type A domain

Domain ID domain_id	3qa3J01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3J02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3K01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3K02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	3qa3L00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	410 — von Willebrand factor, type A domain

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Unit-cell length a length_a	82.604 Å
Unit-cell length b length_b	158.346 Å
Unit-cell length c length_c	233.319 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 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	3.000 Å
Low-resolution limit resolution_low	47.650 Å
R factor r_factor	0.1956
R_work r_work	0.1941
R_free r_free	0.2244

Crystal Structure of A-domain in complex with antibody

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

Integrin alpha-M

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

3qa3__assembly_4__model_1

3qa3__assembly_4__model_1 | I(q)

3qa3__assembly_4__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)

Crystal Structure of A-domain in complex with antibody

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

Integrin alpha-M

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

3qa3__assembly_4__model_1

3qa3__assembly_4__model_1 | I(q)

3qa3__assembly_4__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 40 domains

SCOP 2.08 (20 domains)

CATH v4.4 (20 domains)

7. Citations (1)