1p7k

Crystal structure of an anti-ssDNA antigen-binding fragment (Fab) bound to 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)

Method: X-RAY DIFFRACTION

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

antibody light chain FAB

Mus musculus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	antibody heavy chain FAB × 1 （Q9JL75） SULFATE ION × 6 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID × 1 PENTAETHYLENE GLYCOL × 2 DI(HYDROXYETHYL)ETHER × 2 GLYCEROL × 8 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	antibody heavy chain FAB × 1 （Q9JL75） SULFATE ION × 3 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID × 1 PENTAETHYLENE GLYCOL × 2 GLYCEROL × 8 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q8VCP0
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–214； UniProt 25–234 Author chain L； PDBConstruct 1–214； UniProt 25–234

antibody heavy chain FAB

Mus musculus

UniProt Q9JL75

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	antibody light chain FAB × 1 （Q8VCP0） SULFATE ION × 6 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID × 1 PENTAETHYLENE GLYCOL × 2 DI(HYDROXYETHYL)ETHER × 2 GLYCEROL × 8 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	antibody light chain FAB × 1 （Q8VCP0） SULFATE ION × 3 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID × 1 PENTAETHYLENE GLYCOL × 2 GLYCEROL × 8 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q9JL75_MOUSE
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 5–224； UniProt 1–109 Author chain H； PDBConstruct 5–224； UniProt 1–109

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	1p7k
Deposition date deposition_date	2003-05-02
Structure title title	Crystal structure of an anti-ssDNA antigen-binding fragment (Fab) bound to 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)
Keywords keywords	FAB, ANTIBODY, ANTI-DNA ANTIBODY, AUTOANTIBODY, LUPUS, HEPES, 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.

1p7k__assembly_2__model_1

Assembly 2 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1p7k__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1p7k__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	25.37 Å
Rg (electron density)	24.50 Å
Total Rg	25.34 Å
Atom count	3342
Residues	431
Excluded volume	59325 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1p7k__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1p7k__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 (8)

Entity 1 Entity 1 polymer

Description description	antibody light chain FAB
Molecular weight formula_weight	23616.1 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L,A
Atom count atom_count	7565

ELQMTQSPASLSASVGETVTITCRASENIYSYLAWYQQKQGKSPQLLVYNAKTLAEGVPSRFSGSGSGTQFSLKINSLQPEDFGSYYCQHHYGTPLTFGAGTKLELKRADAAPTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLNSWTDQDSKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRNEC

Source Source

Source organism organism	Mus musculus
Common name common_name	house mouse
NCBI taxonomy ID ncbi_taxonomy_id	10090
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	antibody heavy chain FAB
Molecular weight formula_weight	24153.2 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

QVKLLESGPELVKPGASVKMSCKASGYTFTSYVMHWVKQKPGQGLEWIGYINPYNDGTKYNEKFKGKATLTSDKSSSTAYMELSSLTSEDSAVYYCVRGGYRPYYAMDYWGQGTSVTVSSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAVLQSDLYTLSSSVTVPSSTWPSETVTCNVAHPASSTKVDKKIVPRDCTS

Source Source

Source organism organism	Mus musculus
Common name common_name	house mouse
NCBI taxonomy ID ncbi_taxonomy_id	10090
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	9

Entity 4 Entity 4 non-polymer

Description description	4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
Molecular weight formula_weight	238.3 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	PENTAETHYLENE GLYCOL
Molecular weight formula_weight	238.3 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 6 Entity 6 non-polymer

Description description	DI(HYDROXYETHYL)ETHER
Molecular weight formula_weight	106.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 7 Entity 7 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	syn
Copy count entity_count	16

Entity 8 Entity 8 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	771

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6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (10 domains)

Domain ID domain_id	d1p7ka1
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	d1p7ka2
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	d1p7kb1
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	d1p7kb2
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	d1p7kb3
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	d1p7kh1
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	d1p7kh2
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	d1p7kh3
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	d1p7kl1
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	d1p7kl2
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	1p7kA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kB01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kB02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kH01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kH02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kL01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	1p7kL02
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	107.666 Å
Unit-cell length b length_b	156.703 Å
Unit-cell length c length_c	61.003 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	8

Space group space_group	P 21 21 2
Space-group number int_tables_number	18
Crystal system crystal_system	—

Resolution resolution	1.750 Å
Low-resolution limit resolution_low	48.140 Å
R factor r_factor	0.1970
R_work r_work	0.1970
R_free r_free	0.2300

Crystal structure of an anti-ssDNA antigen-binding fragment (Fab) bound to 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)

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

antibody light chain FAB

State in the Current Structure

Other States of the Same Protein in the Database

antibody heavy chain FAB

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

1p7k__assembly_2__model_1

1p7k__assembly_2__model_1 | I(q)

1p7k__assembly_2__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 (8)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 water

6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (10 domains)

CATH v4.4 (8 domains)

7. Citations (3)

Crystal structure of an anti-ssDNA antigen-binding fragment (Fab) bound to 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)

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

antibody light chain FAB

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

antibody heavy chain FAB

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

1p7k__assembly_2__model_1

1p7k__assembly_2__model_1 | I(q)

1p7k__assembly_2__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 (8)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 water

6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (10 domains)

CATH v4.4 (8 domains)

7. Citations (3)