2iqa

PFA2 FAB fragment, monoclinic apo form

Method: X-RAY DIFFRACTION

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

IgG2a Fab fragment PFA2 Kappa light chain

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	IgG2a Fab fragment PFA2 heavy chain × 1 （Q811U5） ACETAMIDE × 1 GLYCEROL × 4 CHLORIDE ION × 1 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	IgG2a Fab fragment PFA2 heavy chain × 1 （Q811U5） ACETAMIDE × 1 GLYCEROL × 4 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	A2NHM3_MOUSE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–219； UniProt 1–219 Author chain L； PDBConstruct 1–219； UniProt 1–219

IgG2a Fab fragment PFA2 heavy chain

OrganismNot specified

UniProt Q811U5

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	IgG2a Fab fragment PFA2 Kappa light chain × 1 （A2NHM3） ACETAMIDE × 1 GLYCEROL × 4 CHLORIDE ION × 1 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	IgG2a Fab fragment PFA2 Kappa light chain × 1 （A2NHM3） ACETAMIDE × 1 GLYCEROL × 4 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q811U5_MOUSE
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–123； UniProt 1–118 Author chain H； PDBConstruct 1–123； UniProt 1–118

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	2iqa
Deposition date deposition_date	2006-10-13
Structure title title	PFA2 FAB fragment, monoclinic apo form
Keywords keywords	pfa2, wwddd, cdr, IMMUNE SYSTEM; IMMUNE SYSTEM
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.

2iqa__assembly_1__model_1

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

Download this curve (.dat)

2iqa__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2iqa__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	26.03 Å
Rg (electron density)	24.81 Å
Total Rg	25.69 Å
Atom count	3380
Residues	440
Excluded volume	59933 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2iqa__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2iqa__assembly_2__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	IgG2a Fab fragment PFA2 Kappa light chain
Molecular weight formula_weight	24146.8 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L,A
Atom count atom_count	7057

DVLMTQTPLSLPVSLGDQASISCRSSQSIVHSNGNTYLEWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYYCFQGSHVPLTFGAGTKLEIKRADAAPTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLNSWTDQDSKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRNEC

Entity 2 Entity 2 polymer

Description description	IgG2a Fab fragment PFA2 heavy chain
Molecular weight formula_weight	23904.0 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

QVTLKESGPGILKPSQTLSLTCSLSGFSLRTSGMGVGWIRQPSGKGLEWLAHIWWDDDKNYNPSLKSQLTISKDTSRNQVFLKITSVDTADTATYYCVRRAHNVVLGDWFAYWGQGTLVTVSAAKTTAPSVYPLAPVCGGTTGSSVTLGCLVKGYFPEPVTLTWNSGSLSSGVHTFPAVLQSGLYTLSSSVTVTSSTWPSQSITCNVAHPASSTKVDKKIEPR

Entity 3 Entity 3 non-polymer

Description description	ACETAMIDE
Molecular weight formula_weight	59.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 5 Entity 5 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	272

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6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d2iqaa1
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	d2iqaa2
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	d2iqab_
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	d2iqah_
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	d2iqal1
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	d2iqal2
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)

CATH v4.4 (8 domains)

Domain ID domain_id	2iqaA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaB01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaB02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaH01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaH02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaL01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iqaL02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

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Unit-cell length a length_a	77.984 Å
Unit-cell length b length_b	73.412 Å
Unit-cell length c length_c	93.508 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	99.97 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	33.450 Å
R factor r_factor	0.2320
R_work r_work	0.2300
R_free r_free	0.2790

PFA2 FAB fragment, monoclinic apo form

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

IgG2a Fab fragment PFA2 Kappa light chain

State in the Current Structure

Other States of the Same Protein in the Database

IgG2a Fab fragment PFA2 heavy chain

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

2iqa__assembly_1__model_1

2iqa__assembly_1__model_1 | I(q)

2iqa__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (1)

PFA2 FAB fragment, monoclinic apo form

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

IgG2a Fab fragment PFA2 Kappa light chain

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

IgG2a Fab fragment PFA2 heavy chain

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

2iqa__assembly_1__model_1

2iqa__assembly_1__model_1 | I(q)

2iqa__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 water

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (1)